Owens, Albert James v Repatriation Commission [1995] FCA 845

CATCHWORDS

ADMINISTRATIVE LAW - Veterans' Entitlements - whether adenocarcinoma of the colon of the veteran was a war-caused disease - whether "reasonable hypothesis" connecting the disease with the service of the veteran - meaning of "reasonable hypothesis" - what constitutes "known scientific facts", conflict with which will make hypothesis unreasonable - whether Tribunal "considered the whole of the material before it" - whether conclusion of the Tribunal open having regard to the evidence - whether error of law - s.120 Veterans' Entitlements Act 1986 (Cth).

EVIDENCE - judicial notice - whether s.144 Evidence Act 1995 (Cth) alters common law position.

Veterans' Entitlements Act 1986 (Cth) - ss.120(1), (3)

Administrative Appeals Tribunal Act 1975 (Cth) - s.33

Evidence Act 1995 (Cth) - s.144

Arm Constructions Pty Ltd v Commissioner of Taxation (1986) 10 FCR 197

Bell v Repatriation Commission (1992) 26 ALD 545

BTR PLC v Westinghouse Brake & Signal Co (Aust) Ltd (1992) 106 ALR 35

Bushell v Repatriation Commission (1992) 175 CLR 408

Byrnes v Repatriation Commission (1993) 177 CLR 564

Collector of Customs v Pozzolanic Enterprises Pty Ltd (1993) 115 ALR 1

East v Repatriation Commission (1987) 16 FCR 517

Gilbert v Repatriation Commission (1989) 86 ALR 713

Hamling v Repatriation Commission (1989) 19 ALD 354

Horman v Bingham [1972] VR 29

Lowerson v Repatriation Commission (1994) 50 FCR 252

Re Dell and Repatriation Commission (1986) 9 ALD 596

Repatriation Commission v Bushell (1991) 23 ALD 13

Webb v Repatriation Commission (1988) 19 FCR 139

ALBERT JAMES OWENS v REPATRIATION COMMISSION

NG 815 of 1994

Davies, Einfeld & Drummond JJ

27 September 1995

Sydney

IN THE FEDERAL COURT OF AUSTRALIA )

)

NEW SOUTH WALES DISTRICT REGISTRY ) NG 815 of 1994

)

GENERAL DIVISION )

On appeal from a single judge

of the Federal Court of Australia

BETWEEN: ALBERT JAMES OWENS

Appellant

AND: REPATRIATION COMMISSION

Respondent

Coram: Davies, Einfeld & Drummond JJ.

Place: Sydney

Date: 27 September 1995

MINUTES OF ORDER

The Court Orders That:

1. The appeal be allowed.

2. The orders below be set aside and in lieu thereof it be ordered:-

i. That the decision of the Administrative Appeals Tribunal be set aside.

ii. The matter be remitted to the Administrative Appeals Tribunal to be heard and decided again with or without the hearing of further evidence.

iii. The applicant's costs of the proceeding be paid by the respondent.

3. The appellant's costs of the appeal be paid by the respondent.

NOTE: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

IN THE FEDERAL COURT OF AUSTRALIA )

)

NEW SOUTH WALES DISTRICT REGISTRY ) NG 815 of 1994

)

GENERAL DIVISION )

On appeal from a single judge

of the Federal Court of Australia

BETWEEN: ALBERT JAMES OWENS

Appellant

AND: REPATRIATION COMMISSION

Respondent

Coram:Davies, Einfeld & Drummond JJ.

Place: Sydney

Date: 27 September 1995

REASONS FOR JUDGMENT

Davies J:- This is an appeal from a judgment of a judge of the Court, in which his Honour dismissed an appeal from a decision of the Administrative Appeals Tribunal dismissing an application for the review of a decision of the Repatriation Commission given on 3 June 1988, which had refused Mr Owens' claim for a pension in respect of the medical condition, adenocarcinoma of the colon, a condition which the Repatriation Commission held to be not war-caused.

The central issue in the appeal is the operation of s.120(1) and (3) of the Veterans' Entitlements Act 1986 (Cth) which read, inter alia:-

"120(1) Where a claim under Part II for a pension in respect of the incapacity from injury or disease of a veteran, or of the death of a veteran, relates to the operational service rendered by the veteran, the Commission shall determine that the injury was a war-caused injury, that the disease was a war-caused disease or that the death of the veteran was war-caused, as the case may be, unless it is satisfied, beyond reasonable doubt, that there is no sufficient ground for making that determination.

...

(3) In applying subsection (1) or (2) in respect of the incapacity of a person from injury or disease, or in respect of the death of a person, related to service rendered by the person, the Commission shall be satisfied, beyond reasonable doubt, that there is no sufficient ground for determining:

(a) that the injury was a war-caused injury or a defence-caused injury;

(b) that the disease was a war-caused disease or a defence-caused disease; or

as the case may be, if the Commission, after consideration of the whole of the material before it, is of the opinion that the material before it does not raise a reasonable hypothesis connecting the injury, disease or death with the circumstances of the particular service rendered by the person."

These provisions have been considered in many cases including by the High Court of Australia in Bushell v Repatriation Commission (1992) 175 CLR 408; Byrnes v Repatriation Commission (1993) 177 CLR 564 and by this Court in East v Repatriation Commission (1987) 16 FCR 517; Webb v Repatriation Commission (1988) 19 FCR 139; Gilbert v Repatriation Commission (1989) 86 ALR 713; Repatriation Commission v Bushell (1991) 23 ALD 13; Hamling v Repatriation Commission (1989) 19 ALD 354 and Lowerson v Repatriation Commission (1994) 50 FCR 252.

Notwithstanding the elucidation given by the authorities, particularly the decisions in Bushell and Byrnes, difficulties persist in the application of the provisions. The words to which I wish to give special attention, for the purposes of the present appeal, are the phrase appearing in s.120(3), "after consideration of the whole of the material before it". This phrase must be read in the light of ss.17 & 18 of the Veterans' Entitlements Act which cast upon the Secretary to the Department and upon the Commission the task of
enquiring into and determining the relevant facts. Section 120(3) thus directs attention to the facts of the particular veteran's service and circumstances. Section 120(3) requires the Commission to consider whether the material before it raises a reasonable hypothesis connecting the injury, disease or death with the circumstances of the particular service.

In East v Repatriation Commission at 532, Jenkinson, Neaves & Wilcox JJ agreed with the exposition of the provisions by the Veterans' Review Board in Stacey (unreported Nos. V83/0396, V84/0821 and V28/072, 26 June 1985). The Board said:-

"For a reasonable hypothesis to be `raised' by material before the Board, we think it must find some support in that material - that is, the material must point to, and not merely leave open, a hypothesis as a reasonable hypothesis."

That passage was approved in Bushell by Brennan J at 428. In Bushell, Mason CJ, Deane & McHugh JJ at 414 said:-

"The material will raise a reasonable hypothesis within the meaning of s.120(3) if the material points to some fact or facts (`the raised facts') which support the hypothesis and if the hypothesis can be regarded as reasonable if the raised facts are true."

In Byrnes at 569-70, Mason CJ, Gaudron & McHugh JJ said:-

"The statement in Bushell that the material must point to some fact or facts which support the hypothesis means no more than that the material before the Commission must raise some fact or facts which give rise to the hypothesis. When that fact or those facts have been identified, the question for determination is whether the hypothesis is reasonable."

Notwithstanding this comment, the Commission must form its opinion after consideration of the whole of the material before it. From that material as a whole, the Commission must determine whether or not a reasonable hypothesis is `raised'. In this way the hypothesis is judged to be reasonable, not merely as a general theory or possibility, but
as an hypothesis of the cause of the particular veteran's medical condition.

It was submitted by counsel for Mr Owens that the Act contemplated that a reasonable hypothesis could be a theory propounded without regard having been had to the precise details of the veteran's case. Counsel submitted that an hypothesis was merely a proposition and that questions of causation were dealt with not under s.120(3) but under s.120(1). This approach has not been accepted by the cases to which I have referred. Nor is it consistent with the remarks of Mason CJ, Deane & McHugh JJ in Bushell, where their Honours said at 416:-

"But unless the Commissioner is satisfied beyond reasonable doubt that there is no sufficient ground for the factual foundation of the hypothesis, the claim must succeed; we cannot conceive of a case where, for the purpose of s.120(3), the hypothesis is reasonable having regard to the raised facts, yet the Commission could be satisfied, `beyond reasonable doubt, that there is no sufficient ground for making the determination' even though the raised facts are not disproved. Indeed, once there is sufficient factual material to point to a reasonable hypothesis connecting the injury etc. with the operational service, it seems convenient simply to treat the case as governed by the application of s.120(1). If that is done, the claim will succeed unless the Commission is satisfied beyond reasonable doubt that the factual foundation upon which the hypothesis can operate does not exist. cf. Barca v. The Queen (1975), 133 C.L.R. 82, at p.105."

It is implicit in their Honours' remarks that a reasonable hypothesis should be sufficiently related to the facts of the veteran's medical condition to provide some evidence of the necessary causal link with the veteran's service.

In many cases, medical practitioners do not understand the nature of the questions to which they should direct their attention. Many medical practitioners place too much emphasis upon the supposed need for scientific proof. I need not deal with that point in the present case. The evidence given in Bushell is a sufficient example.

Some medical practitioners propound in their evidence a mere theoretical possibility based, not upon a clinical consideration of the veteran's medical condition and of the circumstances of the war service, but on mere theoretical possibilities. Such an approach was criticised in Hamling, where at 358-9 the Court said:-

"Thus, although an hypothesis is merely a theory or proposition and is not required to be proved, it must be `supported by the facts', per Brennan J in O'Brien's case [Repatriation Commission v O'Brien (1985) 155 CLR 422]; `pointed to by the facts', per the court in East's case; or `judged in the light of the circumstances of [the] case', per the tribunal in Re Bramston [Re Repatriation Commission and Bramston (1987) 12 ALD 53]. In applying this principle, the Tribunal in Re Bramston rejected the evidence of Dr PNJ Ironside, in part because, although Dr Ironside had put forward a theory connecting the development of an haemangioma with herbicides, he had not given attention to the particular facts of Mr Bramston's case.

...

In the present case, it was not sufficient for counsel appearing before the Tribunal to establish that there was a general theory held by some reputable orthopaedic surgeons as to the effect of multiple micro-traumata or small injuries upon osteoarthritis. The existence of such a theory would not of itself establish a reasonable hypothesis in the particular circumstances of the veteran's case. It was necessary that an appropriately qualified expert put forward a supposition which, taking into account the nature of osteoarthritis and the particular circumstances of the veteran's case, suggested a causal link between his disabilities and multiple micro-traumata suffered during his war service."

Experience of decisions of the Administrative Appeals Tribunal shows that, in the practical application of s.120, the borderline between evidence which puts forward a reasonable hypothesis having regard to the facts of a particular case and evidence which goes to a mere theoretical or tenuous hypothesis is sometimes reached when the medical practitioner for the veteran gives evidence in terms, not that in his or her opinion there is a causal connection between war service and the veteran's medical condition, but that it is reasonable to theorise that there may be such a connection. In Bell v Repatriation Commission (1992) 26 ALD 545 at 548-9, the Court referred to medical evidence in the form of "my opinion as to whether there is a reasonable hypothesis", "There is sufficient evidence to hypothesise", and "evidence to hypothesise". In Bell, the Court declined to set aside the decision of an Administrative Appeals Tribunal which had preferred to this evidence that of a doctor who had made a careful examination of the known facts of the veteran's service and of his medical condition.

In Mr Owens' case, the Tribunal did not accept that the hypothesis put forward by Professor G.A. Kune was a reasonable hypothesis. The Tribunal said, inter alia:-

"32. We are satisfied beyond reasonable doubt that there is no sufficient ground for determining that the applicant's bowel cancer was war-caused, because we are of the opinion that the circumstances and submissions put before us do not raise a reasonable hypothesis in the alternative connecting his disease with the circumstances of his war-service. This is because neither suggestion that has been made can be called an hypothesis and secondly because, in any event, both suggestions are contrary to the known and established cause of the condition."

In stating that the propositions put forward by Professor Kune did not amount to an hypothesis, the Tribunal had in mind, I think, that Professor Kune propounded a mere theoretical possibility rather than a reasonable hypothesis based upon the facts of Mr Owens' condition.

Mr Owens had suffered amoebic dysentery during his war service, particularly between January and April 1945, and had thereafter suffered from an irritable bowel syndrome resulting in frequent bowel motions. His condition had been sufficiently severe to require him to undergo annual consultations or examinations. In 1986, a diagnosis of carcinoma of the ascending colon was made and a right hemicolectomy operation was performed by a surgeon, Dr T. Hugh.

In a report dated 14 August 1992, Professor Kune referred to Mr Owens' amoebic dysentery but said that there was no evidence that previous amoebic dysentery was
related to cancer of the colon. Professor Kune raised the possibility that Mr Owens may have suffered from mild chronic ulcerative colitis. Professor Kune then turned his attention to the irritable bowel syndrome and said:-

"It has also been suggested that the irritable bowel syndrome can be a predisposing factor in the subsequent development of large bowel cancer. This suggestion makes sense biologically, that is, it is consistent with the concept that someone who suffers from the irritable bowel syndrome for many years with frequent loose bowel motions, may develop structural changes in the lining of the large bowel, leading to hyperplasia of the lining cells, then to dysplasia and neoplastic change, that is, leading to the development of an actual bowel cancer. The difficulty with this suggestion is that up to the present time there have been no systematic studies to either confirm or deny this suggestion.

There is thus some evidence that chronic non-specific diarrhoea is more common in bowel cancer cases than in controls. There is also a biologically plausible suggestion that the irritable colon syndrome/diverticular disease may be one of the predisposing factors in the development of large bowel cancer. Regrettably, a systematic examination of these associations has so far not been made. It is therefore biologically plausible that such an association is a factor in the development of colon cancer.

I would suggest that you or Mr Owens contact Mr Tom Hugh in Sydney and obtain a copy of the pathology report of his right hemicolectomy, as well as any other possible evidence from endoscopy regarding the possibility of previous ulcerative colitis. I would be happy to supply a supplementary report based on any further information." (emphasis added)

Professor Kune was subsequently supplied with information on Mr Owens' pathology findings. In a report of 9 November 1992, Professor Kune reported that Mr Owens had not had ulcerative colitis and therefore that that cause could be ignored. Professor Kune went on to report, however:-

"Since my report of 14 August 1992, no further data has come to hand in the scientific literature regarding the relationship between amoebic dysentery and carcinoma of the colon, diarrhoea/dysentery and carcinoma of the colon, irritable colon syndrome/diverticular disease and carcinoma of the colon, so that my opinion of 14 August 1992 remains unchanged. It is biologically plausible, as I stated in my previous report, that irritable colon syndrome/diverticular disease may be one of the predisposing factors in the development of large bowel cancer. However, there has not been a systematic examination of these associations up to the present time. It is therefore biologically possible and plausible that such an association is a factor in the development of colon cancer, but there are just no data available, either to confirm or to deny this suggestion." (emphasis added)

It will be noted that Professor Kune went no further than to say that the connection between irritable bowel syndrome and the carcinoma was "biologically possible and plausible". Professor Kune did not go on to state that, in his opinion, this was a contributing cause of Mr Owens' cancer. Nor did he refer to any particular aspect of the pathology information to support the connection.

In his oral evidence, Professor Kune referred to two studies in Africa which had raised the possibility that there might be a connection between amoebic infection and bowel cancer. I need not discuss these studies as the Tribunal rejected the amoebic dysentery as a cause of the carcinoma. I see no error of law in the Tribunal's discussion of this matter.

Professor Kune further elaborated on two studies which he had mentioned in his first report:-

"Yes, in our own study we have found it to be more common in a small group of bowel cancer patients versus the controls that we used, this was a control study, and there was one other study in American blacks that have found diarrhoea apparently non-specific. Also more frequent among bowel cancer cases than among their controls, this was another controlled study. Now, in these groups are - we would call them non-specific diarrhoea, and it may be that some of them are - were in fact examples of the irritable colon syndrome or of diverticular disease. The studies did not allow us - the way the study was conducted did not allow us to specifically diagnose each of these conditions. So that my answer to your question is that non-specific diarrhoea, which may include some undiagnosed cases of the irritable colon syndrome and of diverticular disease, has been found to be more common but only in a small number of cases, more common in bowel cancer cases than in controls.

... Well, the reason for saying that is that our study consisted of about 1500 respondents and of those there were 12, 10 cases and two controls who had this past history of diarrhoea, and so the reason for saying that we could not draw firm conclusions is because there were just not sufficient number of cases for us to say, aha, here we have an important difference.

But the term itself, `firm conclusions', as a scientist what does that mean?---Well, it means that we did not think there was enough evidence for what we might call proof."

Professor Kune then expressed the substance of his view as follows:-

" - if there is a relationship my view of how it occurs not why, but how it occurs, would be similar to what I have described previously in that my hypothesis, if there is a relationship between the irritable colon syndrome, irritable bowel syndrome and bowel cancer, is that we do know that there is - this is not a hypothesis, we do know this - that there is excessive and abnormal motility of the bowel, movement of the bowel which is not only excessive but it is also abnormal of the large bowel and there is also an excessive production of both mucous and fluid and both of these are symptomatically evident in people who have the irritable colon syndrome or diverticular disease which is symptomatic. So we know that this does occur and then saying, right, what is happening inside the colon. My view is, my hypothesis is that what is happening is that in order to accommodate for this excessive functioning, we might say, of the bowel, there is an increased rate of multiplication of the lining cells of the large bowel and these are the cells where bowel cancer develops. Then, taking it to the next step, if this does occur, this excessive multiplication of these mucosal cells which is medically called hyperplasia results in an increasing probability of something going wrong during multiplication so that we get abnormal cells - this is a process that is described dysplasia, abnormal appearing cells and we could also then call this a pre-malignant change and then with further multiplication of these abnormal cells, we then have the development of yet another stage which is neoplasia or the development of a tumour, and so - of a malignant tumour, or of a tumour of some type. So, this would be the way [I] envisage that if there is a relationship between the irritable colon syndrome and diverticular disease and colon cancers, this is how it happens." (emphasis added)

Professor Kune gave this evidence:-

"In your view, is that connection or that proposed connection absurd, fanciful or untenable?---I don't think it is absurd or fanciful or untenable, no.

Could it be described as plausible or worthy of further consideration?---Yes, I believe it is plausible and I believe it is worthy of further consideration. As a scientist my difficulty is that regrettably on neither count, neither on amoebic infection nor on the irritable colon diverticular disease aspect, those two separate things, has there been a careful controlled epidemiological study made and that is my difficulty as a scientist. I believe that both of these are worthy of a further consideration and further research, certainly from our community's point of view, further research into the association between irritable colon syndrome and diverticular disease and bowel cancer is certainly worthy of further study." (emphasis added)

It will be noted again that Professor Kune did not express it as his view that there was a causal connection between the irritable colon syndrome and colon cancers but rather that there might be. Professor Kune expressed it to be his opinion that there was a possibility of a connection and that, "if there is a relationship between the irritable colon syndrome and diverticular disease and colon cancers, this is how it happens."

Dr John A Levi gave evidence on behalf of the Commission. His written report, which answered the reports of Professor Kune, stated inter alia:-

"The precise etiology of carcinoma of the colon is unknown, however it is generally considered that there is a genetic predisposition to this condition which is not necessarily associated with a family history, but represents an inherent potential for an individual to develop the condition later in life. This predisposition is usually affected by various environmental influences and in the case of carcinoma of the colon, it is felt that `western' style diets are probably particularly implicated. This involves a relatively high fat, low fibre diet. It is necessary for such dietary influences to be of a long term nature, rather than a short term effect. In other words it is a virtually whole of life effect."

Dr Levi went on to say that:-

"There is no experimental, epidemiological or clinical evidence to support a past history of amoebic dysentery predisposing to the development of carcinoma of the colon. Similar conclusions can be drawn for irritable colon, although this condition can be associated with the development of diverticulosis and diverticulitis which appears to have occurred in Mr Owens' case."

In his oral evidence, Dr Levi displayed a misunderstanding of what is required of a reasonable hypothesis. Dr Levi said for example:-

"...

What I say is that unless one undertakes the study then you do not have any science to support it so that it is contrary.

Is no evidence and contrary the same?---Well, no plausibility, let me put it that way for you."

I have already referred to the fact that a reasonable hypothesis does not necessarily have to be supported by accepted scientific studies. Dr Levi further said:-

" - there is no clinical, experimental or epidemiological evidence to link irritable bowel and diverticular disease to colon cancer.

...

In other words, it is not an impossible idea but it has no credibility ..."

Dr Levi introduced a new factor when he said:-

"Is there anything you would like to add in respect of the documents you have read?---No. No, I think that by far the important point is one which came up in our discussion earlier on and that is that there is, to my mind, good evidence as to the reasons for this man's bowel cancer in that he was shown to have villus adenoma immediately adjacent to his bowel cancer. Villus adenomas are known to be pre-malignant conditions and it is likely that the cancer itself arose from one and it has been well shown that villus adenomas are conditions which arise as developmental problems that have a known inherent tendency. In other words, people are born with them and a portion of them go on to become cancerous.

Given a circumstance such as that, how would or could it operate to displace alternative explanations?---By being the most plausible and known and scientifically recognised explanation for the cause of this man's bowel cancer.

And is that a normally accepted scientific way of disposing of alternative theories?---Essentially one has to take what is known in science and relate it to an individual and when one has a general recognition of a causality, if that is considered to have a regular association with that possibility, that is often accepted. It cannot completely misplace anything else but it does not - it is not possible to say then that those other things are excluded. By the same token, it is reasonable to say that that is by far the most likely factor involved in this man's causation, cancer causation, but you can never exclude other ideas because, as I have said, that nothing is impossible in medicine."

Earlier in his evidence Dr Levi had said:

"In the pathology material which was not provided at the time of my first report but subsequently provided, there is an indication that not only was there a cancer arising from the upper - the lower - the beginnings of the ascending colon and close to the oleo-caecal valve actually would - virtually in the caecum - but also very close [to] that cancer in the immediately adjacent caecum was a polyp which was biopsied or removed at the time that the other pathology was removed and found to be a villus adenoma which is know[n] to be a pre-malignant adenoma - known to be a pre-malignant polyp and therefore it is very likely that there is a correlation between the two." (emphasis added)

Dr Levi referred in particular to a letter from Dr Hugh to Dr B. Squarci of 17 May 1991 which said:-

"I did a right hemicolectomy on the 28th November 1986 for a T3NOMO carcinoma in the right colon. This had arisen in a villous adenoma, and he therefore should have regular (probably annual) colonoscopy as these tumours tend to be multiple."

The Tribunal accepted Dr Levi's evidence in this respect. The Tribunal said:-

"26. He [Dr Levi] made the telling point that the evidence of the operating surgeon, identifying a villous adenoma, would be conclusive of the cause of the applicant's cancer.
This condition indicated to him that the cancer was of genetic origin - that is to say that a known inherent tendency to malignancy was demonstrated by the discovery of this adenoma. In his view, the particular cause of Mr Owens' cancer had been identified and to suggest any other possible cause would be to espouse a theory contrary to known facts. The villous adenoma in his opinion was the most normal and accepted way of explaining the cause of Mr Owens' cancer."

The Tribunal overstated the matter when it used the adjective "conclusive" in the first sentence, but the last sentence expressed the substance of Dr Levi's evidence in this respect. The Tribunal also said:-

"31. A mere possibility, however biologically plausible, falls short of a proposition possessing some degree of acceptability or credibility, if it does not point to, and not merely leave open, the conclusion contended for. It is true that a hypothesis does not require proof. It can not be said, however, that a mere suggestion for research is itself an hypothesis raised by the facts. Neither the tentative papers cited in relation to the amoebic dysentery connection nor the biologically plausible speculation of Professor Kune amount to more than this. In the present case, in any event such a suggestion, even if it amounted to an hypothesis, would be negatived because the facts indicate a clear and recognisable cause for the disease without resort to any suggestion or hypothesis. The fact of the demonstration of the villous adenoma has not been taken into account by the applicant in formulating his alternative hypotheses. They are therefore not based on the raised facts."

An issue of natural justice has arisen because the representative for the Commission did not put to Professor Kune, whilst he was giving evidence, the further matter of the villous adenoma which Dr Levi raised in his oral evidence. Professor Kune apparently left before Dr Levi gave evidence, it having been intimated to the Tribunal that Dr Levi would not be available until 2 p.m.

Although, in a courtroom situation, one would have hoped that all the witnesses would have been fully cross-examined by representatives who were aware of the evidence which their witnesses would give, it must be kept in mind that the Administrative Appeals Tribunal is a body which is not bound by the rules of evidence and in which the proceeding should be conducted with as little formality and technicality and with as much expedition as a proper consideration of the matters before the Tribunal permits. See s.33 of the Administrative Appeals Tribunal Act (1975) (Cth). The Tribunal has many persons appearing before it, either in person or on behalf of others, who may not be fully cognisant of the totality of the issues which may be raised before the Tribunal.

I see no breach of procedural fairness in the proceedings before the Tribunal. There was no objection to the evidence given by Dr Levi and there was no application to call further evidence from Professor Kune, which could, if necessary have been done by affidavit or by telephone hook-up or by video-link.

It is not suggested that any of the material that had been read by Dr Levi had not also been seen by Professor Kune, although it appears that the material was not available to either of them when they made their first written reports. The Tribunal was influenced by the fact that Mr Owens' carcinoma had been a villous adenoma. Dr Levi said this was of significance but Professor Kune did not refer to the fact. In the opinion of Dr Levi, and obviously in the opinion of Dr Hugh, it was a fact which was important to a diagnosis of the nature of the carcinoma.

I agree with the learned trial Judge that the Tribunal was the judge of the facts and arrived at its decision after correctly summarising the evidence before it. There are one or two statements in the Tribunal's reasons which may be overstatements. The Court should not be too technical about these matters. It is important to understand the points which the Tribunal was making rather than to dwell upon the precise words which a busy Tribunal used.

I agree with the trial Judge that, on the facts before it, it was open to the Tribunal to reject the evidence of Professor Kune as propounding a reasonable hypothesis connecting Mr Owens' disease with the circumstances of his particular service. Issues of reasonableness are primarily issues of fact for the tribunal of fact. A determination of "reasonableness" requires the making of a value judgment. I see no error of law in the Tribunal's approach to the question before it or in its decisions. The issue was not whether Professor Kune propounded an hypothesis which, as a matter of general theory, was a reasonable one, but whether, after a consideration of the whole of the material, Professor Kune's hypothesis was a reasonable hypothesis connecting Mr Owens' adenocarcinoma with his war service. In my opinion, having regard to the evidence of Dr Levi and to the lack of specific evidence from Professor Kune referring to a significant known fact of Mr Owens' cancer, it was open to the Tribunal to conclude that Professor Kune's hypothesis was too theoretical and tenuous to be a reasonable hypothesis for the purposes of s.120(3).

I agree with the judgment below. I would dismiss the appeal with costs.

I certify that this and the 13 preceding pages

are a true copy of the reasons for judgment herein of

the Honourable Justice Davies.

Associate:

Date: 27 September 1995

IN THE FEDERAL COURT OF AUSTRALIA)

NEW SOUTH WALES DISTRICT REGISTRY) No. NG 815 of 1994

GENERAL DIVISION )

ON APPEAL from a single Judge of the

Federal Court of Australia

Between: ALBERT JAMES OWENS

Appellant

And: REPATRIATION COMMISSION

Respondent

REASONS FOR JUDGMENT OF JUSTICE EINFELD

INTRODUCTION

The appellant, Albert James Owens, was born on 15 May 1919. He served in the Australian Army between March 1941 and November 1945, for the most part stationed in Papua New Guinea. There he contracted severe amoebic dysentery from which he suffered for ten weeks before treatment became available. It was considered a very serious form of the infection and he was hospitalised for 89 days. In due course he was left suffering with neurogenic diarrhoea or frequent loose bowel motions, a disability accepted as war-caused within the meaning of what is now section 9 of the Veterans' Entitlement Act 1986 (the Act) on 24 December 1945.

Mr Owens was advised to have his bowel condition checked annually, but apart from some treatment in the late 1970s for diverticulitis, no specific new abnormalities were recorded until November 1986 when he underwent an operation by Dr Thomas Hugh
at St. Vincents' Hospital to remove a cancer that had been detected in his bowel, as well as a villous adenoma or polyp in the bowel. The post operative pathology revealed a mild dysplasia in the caecum. Certain disabilities flowing from the amoebic dysentery have over the years been accepted as war-caused including a condition referred to as irritable colon or bowel syndrome, but Mr Owens' claim for a pension for the bowel cancer was refused by the Repatriation Commission on 3 June 1993.

This decision was reviewed by the Veterans' Appeals Division of the Administrative Appeals Tribunal, but in reasons for decision handed down on 26 November 1993, the appeal was refused. Mr Owens then applied to have the decision reviewed by a single Judge of this Court, on a question of law, pursuant to section 44 (1) of the Administrative Appeals Tribunal Act 1975, and on 3 November 1994 Justice Lockhart handed down reasons for judgment dismissing the application. This is an appeal from that decision.

DECISION APPEALED FROM

The case before the learned primary Judge concerned whether the Tribunal had correctly applied the provisions of section 120 of the Act which relevantly provides:

(1) Where a claim under Part II for a pension in respect of the incapacity from injury or disease of a veteran, or of the death of a veteran, relates to operational service rendered by the veteran, the Commission shall determine that the injury was a war-caused injury, that the disease was a war-caused disease or that the death of the veteran was war-caused, as the case may be, unless it is satisfied, beyond reasonable doubt, that there is no sufficient ground for making that determination.

(2) ...

(3) In applying subsection (1) or (2) in respect of the incapacity of a person from injury or disease, or in respect of the death of a person related to service rendered by the person, the Commission shall be satisfied, beyond reasonable doubt, that there is no sufficient ground for determining:

(a) that the injury was a war-caused injury or a defence-caused injury;

(b) that the disease was a war-caused disease or a defence-caused disease; or

(c) that the death was war-caused or defence-caused;

It is now settled law that this section first requires the establishment or identification of a reasonable hypothesis linking the condition under consideration with the relevant war service of the veteran: Bushell v Repatriation Commission [1992] 175 CLR 408 at 414-5 and 428; Byrnes v Repatriation Commission [1993] 177 CLR 456 at 571. The Tribunal having determined that no reasonable hypothesis existed, Justice Lockhart summarised the consequent legal position at AB 199:

The Tribunal decided that the material before it did not raise a reasonable hypothesis connecting the operational service of the applicant with his incapacity, so that there was nothing upon which it could find that the incapacity was war-caused within
the meaning of s 120(1). If the material had raised such a hypothesis, the operation of subsection (3) would have been spent and the matter would have fallen for determination in accordance with subsection (1). The Tribunal did not reach that point because of its finding that the material did not raise a reasonable hypothesis connecting the operational service with the incapacity. Hence the claim had to fail before the Tribunal.

The appellant submitted to Justice Lockhart that:

1. the Tribunal incorrectly rejected the veteran's claim under section 120(3) of the Act, without applying a section 120(1) standard of disproof beyond a reasonable doubt;

2. the Tribunal erred when giving two reasons why the hypothesis led for the applicant did not satisfy section 120(3). These reasons were that no hypothesis had been led, and in any event they were contrary to the known cause of the condition. The reasons were contrary to the interpretation of `reasonable hypothesis' given in Bushell;

3. the Tribunal erred in that the second reason given for rejecting the hypothesis as reasonable was incorrectly considered under section 120(3) and should have been considered under section 120(1);

4. there was no disproof of the hypothesis beyond reasonable doubt.

His Honour's review of the evidence led him to agree with the Tribunal that what had been raised was not a hypothesis. At AB 204-5 he said:

... I agree with the Tribunal that what is in essence merely a suggestion for research cannot be itself a hypothesis on the material before the Tribunal in this case. Professor Kune's hypothesis as to the causative link between amoebic dysentery or irritable colon syndrome and the applicant's cancer of the colon is a "hypothesis" in the sense that it is a possibility and it can not be described as fanciful or absurd; but the Professor adds there has been no systematic study to his knowledge carried out, so that there is no evidence to suggest the requisite link.

In this context it is plain that the term `evidence' was referring to what was described in Bushell as the "raised facts". In other words, the finding was that no reasonable hypothesis was raised by the facts. In view of his Honour's decision on this question, it was not necessary to consider the issues raised by subsection (1) of section 120.

GROUNDS OF APPEAL

On this appeal the appellant challenged the determination of the Tribunal and Justice Lockhart that no reasonable hypothesis had been raised connecting the cancer of the colon to war service. He contended that this determination was erroneous in law because:

1. it misapprehended what was required by section 120(3) of the Veterans' Entitlement Act 1986 for a hypothesis to be reasonable;

2. it involved weighing the evidence of the appellant's expert, Professor Gabriel A Kune, against the evidence of the respondent's expert, Dr John A Levi;

3. alternatively, the Tribunal denied the applicant procedural fairness by allowing the case to be determined without it being put to Professor Kune that his opinions had been expressed in ignorance of the findings of the operating surgeon that the appellant had a villous adenoma or that such a finding was inconsistent with opinions advanced by Professor Kune as to the possible causes of the appellant's carcinoma; and

4. further in the alternative, the Tribunal found without evidence and unreasonably that Professor Kune had not taken into account the villous adenoma in formulating his hypothesis.

The first question for determination in this appeal is whether the refusal to find a reasonable hypothesis manifested legal error.

1. A reasonable hypothesis

In Bushell v Repatriation Commission [1992] 175 CLR 408 at 414, Mason CJ, Deane and McHugh JJ said:

The material will raise a reasonable hypothesis within the meaning of s 120(3) if the material points to some fact or facts ("the raised facts") which support the hypothesis and the hypothesis can be regarded as reasonable if the raised facts are true.

The High Court further explained the position in Byrnes v Repatriation Commission [1993] 177 CLR 456 at 571:

The position may be summarised as follows: (1) First, sub-s (3) of s 120 is applied: do all or some of the facts raised by the material before the Commission give rise to a reasonable hypothesis connecting the veteran's injury with war service? The hypothesis will not be reasonable if it is contrary to known scientific facts, or is obviously fanciful or untenable. If the hypothesis is unreasonable the claim fails. Proof of facts is not in issue at this point. (2) If a reasonable hypothesis is established, sub-s (1) of s 120 is applied.

Justice Beazley and I, with whom Justice Neaves agreed, said of subsection (3) in Lowerson v Repatriation Commission [1994] 50 FCR 252 at 260:

In other words the subsection requires the decision maker to assume the raised facts to be true for the purpose of determining whether the hypothesis is reasonable, in the sense that it is not "obviously fanciful, impossible, incredible or not tenable or too remote or too tenuous": East v Repatriation Commission (supra) at 532. That is why the subsection does not speak of any standard of proof or satisfaction for the decision-maker to find that the raised facts exist.

2. The hypotheses in this case

Professor Kune, Emeritus Professor of Surgery at the University of Melbourne, and an expert in the field of diagnosis and treatment of cancer, gave evidence both in writing and in oral testimony before the Tribunal, that it was biologically plausible that irritable bowel syndrome could be a predisposing factor in the development of large bowel cancer. In essence the explanation posited was that someone who has suffered for a long time from irritable bowel syndrome and frequent loose bowel motions may develop structural changes in the lining of the large bowel, leading to hyperplasia or excessive functioning, then to dysplasia and finally neoplastic change. This hypothesis is based upon scientific knowledge and information relating to the development of other cancers. Where there is hyperplasia, there is an increased risk of cancer developing.

Two reports of Professor Kune were before the Tribunal. At the time of his first report dated 14 August 1992, the Professor was unaware of any evidence to support a conclusion that amoebic dysentery is related to cancer of the colon. However, he subsequently made a detailed search of the literature on the subject and concluded that this hypothesis was also biologically plausible. The possible mechanisms included structural changes in the lining of the bowel produced by amoebic infection, and a reduced immunity being associated with the amoebic infection. This was documented in a further report dated 22 February 1993 and repeated in oral testimony before the Tribunal. The
Professor noted in particular two articles published in medical journals, the first by Mr A. Abioye of the Department of Pathology, University College Hospital, Ibadan, Nigeria and the second by Dr E. Camacho of the Faculty of Medicine, University of Guadalajara, Mexico. Neither of these articles offered conclusive proof of a causal connection between previous amoebic infection and cancer, but each author identified factors that pointed to such a conclusion. To date, no systematic study has been done to confirm or disprove this theory.

Although there was no evidence of any finding of hyperplasia or other signs of structural change in the lining of the appellant's bowel cell -- indeed it was suggested from the bar table that such changes are unlikely to be noticed without specific testing -- both suggested hypotheses are otherwise consistent with the appellant's medical history. Professor Kune had also originally postulated that the veteran had ulcerative colitis or chronic inflammation of the colon but he later withdrew the opinion in the light of Dr Hugh's operative and subsequent findings.

On the other hand, Dr Levi, Head of the Department of Clinical Oncology at the Royal North Shore Hospital, considered that in the light of the villous adenoma which the operating surgeon had removed, the most plausible and scientifically recognisable explanation for the cause of Mr Owens' cancer was that it was genetic in origin.

The appellant submitted that the hypotheses supported by the raised facts were that his cancer was either caused by the amoebic dysentery or by the irritable colon syndrome. The Commission contended first that neither of these particular hypotheses was ever put, at least not by Professor Kune. It asserted that the highest the hypotheses reached was that "if" the colon cancer was caused by the war service, then Professor Kune gave a biological explanation of how it might or would have happened. There is no magic in how a hypothesis is presented. At the very least the Professor's biological explanation provides support for these hypotheses. My interpretation of Professor Kune's evidence is, however, that he did advance the hypotheses by asserting that whilst the projected mechanism could not be proved scientifically, it was consistent with all the known medical facts and expertise and was a real possibility in this case.

3. The Tribunal's approach

The Tribunal expressed its conclusion in this way:

We are satisfied beyond reasonable doubt that there is no sufficient ground for determining that the applicant's bowel cancer was war-caused, because we are of the opinion that the circumstances and submissions put before us do not raise a reasonable hypothesis in the alternative connecting his disease with the circumstances of his war-service. This is because neither suggestion that has been made can be called an hypothesis and secondly because, in any event, both suggestions are contrary to the known and established cause of the condition.

Before Justice Lockhart and again on this appeal, it was submitted that the Tribunal had conflated the tests of subsections (3) and (1) of section 120. The language employed does give rise to some confusion. In my view the Tribunal's reasons can be interpreted either as a merging of the tests (which would be incorrect), or the adoption of a two stage reasoning process, viz:

(a) no tenable hypothesis was raised, in the sense that the raised facts did not support what was put forward, and therefore the subsection (3) test was not met

(b) in the event that this finding was wrong, and one or other of the hypotheses was tenable, it was in conflict with known scientific facts and therefore failed the subsection (1) test

It is my belief that the two stage construction is the proper way to interpret the Tribunal's determination. With regard to the first stage, the Tribunal considered that Professor Kune had not taken into consideration the presence of the villous adenoma and therefore that neither of his hypotheses was supported by the raised facts.

In my opinion the Tribunal's conclusion that Professor Kune had not considered the villous adenoma is not a basis to conclude that his hypotheses were not based upon the raised facts. As Lowerson highlighted at 261, the fact that some evidentiary
material may tend to disprove the hypothesis will not of itself be sufficient to make a hypothesis untenable. Bushell made expressly clear that the raised facts are those which support the hypothesis, not all the material presented on the subject under consideration. Again in Lowerson at 263:

As will not infrequently happen, some of these facts might tend to disprove the hypothesis, or do so at least as much as they assist to establish it. To the extent that they are in the former category they are not "raised facts" because they do not support the hypothesis.

Thus what subsection (3) asks is whether the hypothesis is supported or pointed to by the raised facts, not whether there are any other facts that might tend to disprove the hypothesis or whether the hypothesis is raised by each and every fact presented. In my opinion, the Tribunal erred in this regard and misapplied the test under subsection (3).

There was a suggestion in argument that the Tribunal considered the hypotheses unreasonable because they were perceived to be inconsistent with the existence of the villous adenoma. In my view it would be a misapplication of the subsection (3) test to apply such reasoning. The mere presence of an inconsistent fact will not make a hypothesis unreasonable for the purposes of subsection (3). What are of relevance are the facts that point to the suggested hypothesis. Their reliability or acceptability is not to be challenged or considered until the Tribunal comes to determine whether it is satisfied beyond reasonable doubt that they are unproved ("do not exist" -- see Bushell at 416 later).
Even then, a comparison of competing theses will have only a limited role in the process to be carried out. I shall return to those considerations later in these reasons.

4. The raised facts

Assessment of a hypothesis as reasonable or not thus begins with an identification of the "raised facts", i.e. the evidentiary material pointing to and supporting the hypothesis as being reasonable. If the evidentiary material does not point to the hypothesis, the suggested hypothesis is not tenable and is hence unreasonable for the purposes of subsection (3).

In this case the appellant's cancer is a type for which three possible causes are scientifically accepted:

(a) a hereditary or genetic predisposition which may or may not be associated with a family history

(b) a particular diet, often referred to as `western style'; and

It is not suggested that these factors are the only contributors to the development of this type of cancer, but that there is scientific evidence that they are causally linked to the cancer. They clearly do not point to either of the hypotheses proposed.
Moreover, according to Dr Levi, the presence of a villous adenoma in the bowel supports the genetic origin of the cancer.

On the other hand, there was evidentiary material of these facts:

(a) The veteran contracted amoebic dysentery while on, and admittedly caused by, his war service.

(b) His disease was very serious and has caused him to have frequent loose bowel motions ever since.

(d) This condition is known to cause changes in the lining of the large bowel.

(e) Such changes increase the risk of bowel cancer.

(f) The veteran contracted bowel cancer which was operated on in 1986.

5. The "raised facts" and the hypotheses

In view of the problems for interpretation section 120 continues to cause, it cannot be stressed too often how important it is not to engage at this stage in a weighing up of contradictory evidence but to limit the analysis to whether the facts raised by the evidentiary material in the case do or do not point to and support the hypotheses that either amoebic dysentery or irritable bowel syndrome caused the veteran's cancer. As the summary of the raised facts identifies, there are factors pointing to the hypotheses that the cancer was so caused. At least one specialist eminent in the field considered that it was consistent with the particular medical history of the veteran and existing scientific knowledge that either of his conditions, especially the irritable bowel, predisposed him to the cancer and offered a scientific mechanism for how it would probably have occurred, supported by some if limited studies in countries where, unlike Australia, the conditions are apparently reasonably common.

It is not a question of how suggestive of the proposed hypotheses the raised facts have to be. As was noted in Bushell, neither scant evidence nor lack of support will make a hypothesis, raised by the facts and propounded by an expert in the field, unreasonable. At 414:

Clearly enough, a relevant consideration in forming an opinion whether a particular hypothesis is reasonable is whether, as a matter of common or medical experience, the occurrence of an injury etc. of the kind sustained by the veteran is commonly accompanied by or associated with the occurrence of raised facts of the kind which constitute the relevant incidents of the service of the veteran. However, a hypothesis may still be reasonable even though such an accompaniment or association is not demonstrated or even if it is shown to be uncommon. So in determining whether a hypothesis is reasonable for the purpose of s 120(3), it is not decisive that a connexion has not been proved between the kind of injury which occurred and circumstances of the kind which constitute the relevant incidents of the veteran's service. Nor is it decisive that the medical or scientific opinion
which supports the hypothesis has little support in the medical profession or among scientists...

It is true that the facts raising the hypotheses in this case are meagre, but this does not mean that they are non existent. The learned primary judge relied on the absence of a "systematic study" of these conditions to support his conclusion that there was "no evidence to suggest the requisite link". But in a case where the suggested genesis of the conditions is rare in Australia and other developed societies, it is with respect difficult to imagine what other evidence might be expected to be available to support these theses. The precipitating causes of many conditions, such as for example the relationship of physical effort to cardiac infarctions, now widely accepted, were originally not scientifically provable other than by the intuitive reasoning of experts in the fields. Yet in circumstances requiring a much higher standard of proof than applies here, they were not rejected because of an absence of scientific proof. Very substantial awards of compensation of one kind or another were made on this "unscientific" basis.

The Commission submitted to the Tribunal, to Justice Lockhart and on this appeal, that Professor Kune was not aware of the fact that Mr Owens had a villous adenoma. It argued that thisfinding negatived the Professor's theory, as the villous adenomawas said by Dr Levi to point to a cause of the cancer at oddswith it. To meet this argument, the appellant sought to adduceadditional evidence on this appeal in the form of an affidavit from Mr Sherlock, presumably designed to prove in some way that Professor Kune took the villous adenoma into account in the formation of his opinions. When the respondent conceded that Professor Kune was in possession of Dr Hugh's report, though not that he had taken the villous adenoma into consideration, the appellant did not press the application to admit the evidence.

Whether or not the existence of the villous adenoma negatived both proposed hypotheses, the first thing to say about this aspect of the dispute is that the matter is properly the subject of analysis under subsection (1), not at the subsection (3) stage where it is important merely to consider the raised facts and determine if they point to a hypothesis that is reasonable, in the sense that it is not absurd or too tenuous.

In any event, in his report of 14 August 1992 to Mr Sherlock, the advocate from the Legal Aid Commission who appeared for Mr Owens before the Tribunal, Professor Kune suggested amongst other things that a copy of the operating surgeon's pathology report be obtained. Dr Hugh's records and report (AB 130 and 137) noted that Mr Owens had the villous adenoma. In a letter dated 9 November 1992 Professor Kune thanked Mr Sherlock for forwarding additional information including the "pathology findings". This material, which was before the Tribunal, simply cannot be ignored on some technical or forensic basis.

Moreover, at the Tribunal hearing Professor Kune was asked by Member Vice Admiral Leach whether or not his theory concerning ulcerative colitis could be dismissed in light of Dr Hugh's pathology report. Professor Kune answered, as he had in his letter to Mr Sherlock, that it could be (AB 77). These facts suggest to me that Professor Kune not only had a copy of Dr Hugh's report but that he had read it, thus clearly implying that he was aware of the villous adenoma.

There is another factor which bears on this question. Sections 120 of the Act and 33(1)(b) and (c) of the Administrative Appeals Tribunal Act 1975 insist on a regime for the determination of cases such as this in a way that avoids legalism and technicality. This requirement was noted in the joint judgment in Lowerson at 269:

The legislative intention was aimed, as a matter of public policy, at assisting claimants to succeed without being subjected to strict or legalistic proof of the hypotheses they raise.

The Tribunal transcript reveals that Professor Kune's evidence to the Tribunal took place before Dr Levi's and that the Tribunal's hearing was conducted in Sydney. This Court was informed that the Professor had returned to Melbourne when Dr Levi's evidence concluded and that he was for this reason not recalled. If the order of witnesses had been reversed, there can be no doubt that Dr Levi's causative theory or explanation would have been specifically put to Professor Kune in the witness box, as it undoubtedly should have been in any event. It is inconceivable to me that Parliament intended that veterans' pension cases be determined on such chance occurrences.

Professor Kune's suggestion of a causative link between the cancer and either the amoebic dysentery or the irritable bowel syndrome was described by Justice Lockhart, I believe with respect correctly, as neither fanciful nor absurd. However, both the Tribunal and the learned primary Judge appear to have been looking for more than its mere proposition by Professor Kune in order for it to satisfy the reasonable hypothesis test of section 120(3). As the Tribunal said (AB 170):

The mere fact that Professor Kune is eminent in the relevant field of knowledge (and there is no question that he is) is not sufficient to support an hypothesis in these circumstances.

This statement should be contrasted with this remark in Bushell on which it was obviously based (414):

... the case must be rare where it can be said that a hypothesis, based on the raised facts, is unreasonable when it is put forward by a medical practitioner who is eminent in the relevant field of knowledge.

In my most respectful opinion, the Tribunal's approach, and his Honour's previously quoted categorisation of Professor Kune's views as merely "a suggestion for research", placed a considerably higher burden on the appellant than the Act required. The hypotheses were mooted by an expert in the field, are not too tenuous or absurd, are corroborated by other experts' research, and fit the veteran's medical history. Whatever conclusion is reached on the question whether Professor Kune had or had not taken the villous adenoma into his consideration, it is in my view a misinterpretation of Bushell and Byrnes to include in the raised facts Dr Levi's conclusion from the presence of the adenoma. I believe that sufficient credible facts support the hypotheses, and that the hypotheses are reasonable.

6. The hypotheses and s 120(1)

The second question raised in the appeal was whether the Tribunal erred in its application of the onus of disproof in section 120(1). Great weight was placed by the Tribunal on what it described as the `telling point' of Dr Levi's opinion that the villous adenoma was the most plausible and scientifically realistic view of the cause of the cancer. As I have more than once already remarked, it is not entirely clear whether the Tribunal considered this fact as a mechanism to weigh up the reasonableness of the hypothesis under subsection (3) or dealt with it under subsection (1). The Tribunal did record its acceptance of the further statement in Bushell at 415:

Conflict with other medical opinions is not sufficient to reject a hypothesis as unreasonable.

Yet on one reading of the Tribunal's determination, advocated for the appellant, that is precisely what the Tribunal did. In fact any such conflict has nothing to do with the finding of a reasonable hypothesis. The learned primary Judge appears not to have considered this matter at all because his Honour took the view that the Tribunal considered Professor Kune's hypothesis untenable in the subsection (3) sense, i.e. not raised by the facts and hence there was no need to proceed to subsection (1).

Although, as has been seen, I agree on balance with his Honour's interpretation of the Tribunal's determination, it cannot be doubted that the Tribunal's rejection of the hypotheses of Professor Kune was certainly affected by, if not considered in the light of, Dr Levi's explanation. The Tribunal was apparently convinced that Dr Levi's assertion of a scientifically supported conclusion of a genetic origin for the cancer was definitive. It therefore concluded that any other proposition was not only not raised by the facts but was also false because it was inconsistent with known scientific facts. In my view, not only were both of these conclusions unavailable, they evidenced a misconception of the legal task the Tribunal was required to perform at the time.

The definitional summary by the High Court in Byrnes, extracted in part earlier, relevantly continued at 571:

(2) If a reasonable hypothesis is established, subs(1) of s 120 is applied. The claim will succeed unless:

(a) one or more of the facts necessary to support the hypothesis are disproved beyond a reasonable doubt; or

(b) the truth of another fact in the material, which is inconsistent with the hypothesis, is proved beyond reasonable doubt, thus disproving beyond reasonable doubt, the hypothesis.

In Bushell at 416, Mason CJ and Deane and McHugh JJ expressed the concept this way:

... unless the Commission is satisfied beyond reasonable doubt that there is no sufficient ground for the factual foundation of the hypothesis, the claim must succeed; we cannot conceive of a case where, for the purpose of section 120(3), the hypothesis is reasonable having regard to the raised facts, yet the Commission could be satisfied, "beyond reasonable doubt, that there is no sufficient ground for making the determination" even though the raised facts are not disproved. Indeed, once there is sufficient factual material to point to a reasonable hypothesis connecting the injury etc, with the operational service, it seems convenient simply to treat the case as governed by the application of section 120(1). If that is done, the claim will succeed unless the Commission is satisfied beyond reasonable doubt that the factual foundation upon which the hypothesis can operate does not exist.

Commenting on some of these words, the joint judgment in Lowerson further explained at 261:

One of the problems to have arisen in the very difficult task of interpreting s 120 is the concept of "facts" which do or do not exist. It is at least confusing, if not more, to speak of a true or false (or untrue) "fact". What is really being referred to is evidentiary material, in an administrative law sense, which suggests a particular factual conclusion. It is this material which may be shown to be true or untrue in the exercise to be performed under subs (1); that is, to adapt the language of Byrnes, a piece of factual material needed to sustain the hypothesis may be disproved, or ..... a necessary fact inconsistent with the hypothesis may be proved, beyond a reasonable doubt.

The alternate explanation of Dr Levi could thus only have been relevant to prove an inconsistency with the hypotheses pointed to by the raised facts, and to prove its truth beyond a reasonable doubt. Whilst the Tribunal apparently considered Dr Levi's explanation passed both these hurdles, I have been able to find no evidence to support such conclusions. What was established was that the presence of the villous adenoma pointed to Dr Levi's thesis but did not negate the hypotheses of Professor Kune. Dr Levi could not, beyond reasonable doubt, confirm that the veteran's cancer was genetic in origin, or establish that it was not a consequence of his amoebic infection or its sequelae. The presence of the adenoma merely indicated a genetic predisposition; it did not disprove any alternate aetiology.

Additionally, Dr Levi appeared to disapprove of the Kune hypotheses because of a lack of evidence (AB 92), which is a far cry from rejecting them as scientifically inconsistent with known facts. Although Dr Levi in fact conceded that ongoing serious inflammation of the bowel can ultimately lead to bowel cancer (AB 88):

and we in fact know that also from other studies that have been done in other areas of chronic inflammation of the bowel such as ulcerative colitis and Crohn's disease, and it is well shown in western societies and throughout the world that people that have severe ongoing chronic inflammation of the bowel have a higher risk of developing bowel cancer.

he did not consider that the veteran's condition could be described as ongoing chronic inflammation. As it happens, in his second report and during the hearing, Professor Kune resiled from an originally contradictory view, so that both experts came to
agree on the point. But what is essentially relevant from this discussion is that at no stage did Dr Levi assert that the Kune hypotheses have been disproved, nor that the presence of the villous adenoma is itself the requisite disproof. Dr Levi maintained that the Kune hypotheses have not been proven, with which the Professor himself also agreed.

But as the Tribunal correctly noted, proof of the hypotheses is not required. Subsection (1) requires their disproof beyond reasonable doubt or, in this case, at least proof beyond a reasonable doubt that the presence of the villous adenoma or some other fact(s) negatived the raised facts and thus destroyed the otherwise reasonable hypotheses to which they had pointed. The Tribunal's adoption of Dr Levi's proposition did not manifest itself in findings of that kind, and in my opinion, the evidence did not reach anything of that order. Moreover, the Tribunal erred in its conclusion that the hypotheses suggested for this veteran were contrary to the `known and established cause of the condition' because that is not what Dr Levi's evidence established.

7. The remedy

Ordinarily such a conclusion would enable this Court to order that the claim be paid and not that it be remitted for further hearing on the point by the Tribunal. However, I am persuaded by the careful argument of Justice Drummond, whose judgment I have had the benefit of reading, that despite the further delays
that will thereby be occasioned to the appellant when an ultimately favourable conclusion appears clear, this Court is not strictly in a position to exclude definitively the alternative conclusion because Professor Kune's express evidence on the matter has not yet been given and definitive findings have not been made.

CONCLUSIONS

My opinions are that:

1. the Tribunal misapplied section 120(3) and the learned primary Judge erred in concluding that there was no evidence to support Professor Kune's hypotheses;

2. the raised facts support the hypotheses that the cancer was caused either by the amoebic dysentery or, more likely, the irritable bowel syndrome;

3. these hypotheses are not fanciful or absurd;

4. the hypotheses are therefore reasonable;

5. the erroneous conclusion formed by the Tribunal that Dr Levi's evidence of a genetic basis for the appellant's colon cancer amounted to a known scientific fact which negated any hypothesis of its nexus with his war service meant that it
made no finding as to whether that evidence disproved Professor Kune's hypotheses beyond a reasonable doubt;

6. the views formed by the Tribunal of Dr Levi's evidence require the hearing of Professor Kune's evidence on the point so that a conclusion can be reached beyond a reasonable doubt on whether there is no sufficient ground for determining that the appellant's bowel cancer was war-caused.

I agree with the orders proposed by Justice Drummond.

IN THE FEDERAL COURT OF AUSTRALIA) No. NG 815 of 1994

NEW SOUTH WALES DISTRICT REGISTRY)

GENERAL DIVISION )

ON APPEAL FROM A JUDGE

OF THE FEDERAL COURT OF AUSTRALIA

BETWEEN: ALBERT JAMES OWENS

Appellant

AND: REPATRIATION COMMISSION

Respondent

Coram: Davies, Einfeld and Drummond JJ

Place: Sydney

Date: 27 September 1995

REASONS FOR JUDGMENT

DRUMMOND J:

The first question in this appeal is whether the Administrative Appeals Tribunal ("the Tribunal") erred in law in concluding, in the context of ss. 120(1) and (3) the Veterans' Entitlements Act 1986 (Cth) ("the Act"), that the material before it did not raise a reasonable hypothesis connecting the appellant's adenocarcinoma of the colon with his war service.

What must be shown before a reasonable hypothesis within the meaning of that phrase in s. 120(3) of the Act is raised has been the subject of much discussion in cases in the Tribunal and in this Court. More recently, the matter has been considered by the High Court, in Bushell v Repatriation Commission (1992) 175 C.L.R. 408 and Byrnes v Repatriation Commission (1993) 177 C.L.R. 564.

It was submitted that the question whether or not a hypothesis is reasonable is a question of fact for the Tribunal. I do not think that what the High Court said in Bushell at 414-415, about when a reasonable hypothesis will arise for the purposes of s. 120(3) of the Act, does anything more than identify what is comprehended by the expression according to its usage in ordinary English speech. The question of the reasonableness of a hypothesis is therefore one of fact and it follows that it is only if the Tribunal's decision that such a hypothesis was not raised by the material before it was itself unreasonable, in the Wednesbury sense, that the Tribunal's determination would involve a reviewable question of law under s. 44 the Administrative Appeals Tribunal Act 1975 (Cth). See Collector of Customs v Pozzolanic Enterprises Pty. Ltd. (1993) 115 A.L.R. 1 at 10.

I take the facts from the Tribunal's decision and from the medical reports that were before the Tribunal. The appellant, who was born in 1919, served in the army for over four and a half years, until his discharge in November 1945. He contracted amoebic dysentery while on active service in New Guinea. As a result, he was hospitalised for periods between January and April 1945 that totalled 89 days. Although there is no suggestion that the infection that caused his dysentery persisted after his last discharge from hospital in April 1945, the Tribunal found that: "[a]fter these repeated episodes of amoebic dysentery Mr. Owens was left suffering from neurogenic diarrhoea, which in effect meant a constantly loose bowel". On army medical advice, the appellant had his bowel checked annually, but until 1986 no abnormality was detected, "apart from the continuing general non specific diarrhoea". The appellant then consulted a gastroenterologist because of lower abdominal pain. A colonoscopy carried out on 27 November, 1986 "revealed evidence of a large spastic sigmoid colon considered to be related to diverticular disease and the presence of a large ulcerating polypoid carcinoma in the proximal ascending colon just above the caecum". A surgeon, Dr. Hugh, performed a right hemicolectomy on 28 November, 1986. The report to Dr. Hugh dated 2 December, 1986, by the pathologist who examined material removed in this operation, refers to a tumour in the caecum and a benign villous adenoma, in the form of a polyp, showing mild dysplasia which was also found in the caecum. Dr. Hugh commented in a report of 27 July, 1987 to the appellant's then general practitioner, Dr. Drew, that as the appellant had a villous adenoma, he should have a colonoscopy later in 1987.

It is not in dispute that the appellant's amoebic dysentery and his irritable bowel were both war-caused. The Tribunal's attention was therefore focused on whether the
material raised a reasonable hypothesis that linked the appellant's cancer with either of these two conditions.

The appellant relied on Professor Kune, a surgeon with very extensive experience in both the treatment of bowel cancers and in research into the causes, diagnoses and treatment of various common cancers, to support his case that his cancer was war-caused. In his early reports to the appellant's legal adviser, Professor Kune was not prepared to suggest the possibility of any link between the appellant's amoebic infection and his cancer; he then discovered two articles in the medical literature that described an association between amoebic infection of the bowel and bowel cancer. The Tribunal summarised his evidence in this regard as follows:

"17.On the basis of these 2 papers, Professor Kune arrived at a conclusion in relation to the amoebic dysentery connection. He was not prepared to say that there was a definite causal or contributory connection between the 2 conditions. As he pointed out, neither of the 2 authors who have been quoted, were definite in their conclusions. All that both had done was to float the possibility of an idea which has since not been followed up, either by the authors or by any other published researcher.

18. Professor Kune was prepared to say that if there was a connection, then he could suggest a possible mechanism of how amoebiasis may be related to colorectal cancer. These mechanisms would include structural changes produced by the amoebic infection in the lining of the bowel and a lower level of immunity being associated with amoebic infection and perhaps also further lowering immunity when the infection actually occurs." (Tribunal's

emphasis)

The Tribunal summarised Professor Kune's evidence concerning the appellant's irritable bowel syndrome and his cancer in this way:

"23.The other possible hypothesis related to the applicant's irritable bowel syndrome. Professor Kune could not point to any literature in support of such an hypothesis. He explained that he reached his conclusion by reference to other types of cancer in which hyperactivity sometimes resulted in a carcinogic effect. It seemed logical to him that excessive bowel movements and diarrhoea could lead to excessive multiplication of lining cells, which could lead to the likelihood that `something could go wrong'. Excessive activity could lead to the production of abnormal cells, some of which could possibly be malignant. On the basis of what was suggested in Mr Abioye's article in relation to amoebic dysentery, he also postulated, in relation to irritable bowel syndrome, that increased activity could lead to a change in the level of immunity with the possibility that `something may go wrong in multiplication of cells'. He agreed that there have been absolutely no studies made of the possible connection, although he said that there had been discussion on the subject in circles in which he moved. He agreed that what he postulated was the possibility of a connection that was worth exploring, based on clinical evidence in relation to other carcinomas.

24. As he put it - if there was a relationship, then his hypothesis of the mechanics would be that there would be excessive production of mucous and fluid (hypoplasia) which would increase the possibility of abnormal cell changes. He said that this is how he imagines the association might develop and that the longer the increased activity went on, the greater the chance of association. He thought that the possible connection was plausible and that it was worth further consideration. He said he would not say that there is certainly no relationship, but he could go no further than saying that it was a possible relationship which one might entertain. He affirmed his previous use of the term "biologically plausible". (Tribunal's emphasis)

After reviewing all the evidence, including that given by Dr. Levi, another very well qualified cancer specialist called by the respondent, and after referring to relevant authorities, including Bushell v Repatriation Commission, supra, Byrnes v Repatriation Commission, supra, and East v Repatriation Commission (1987) 16 F.C.R. 517, the Tribunal said, of Professor Kune's opinions:

"In our view both of the alternative hypotheses put before us are too tenuous.

...

A mere possibility, however biologically plausible, falls short of a proposition possessing some degree of acceptability or credibility, if it does not point to, and not merely leave open, the conclusion contended for. It is true that a hypothesis does not require proof. It can not be said, however, that a mere suggestion for research is itself an hypothesis raised by the facts. Neither the tentative papers cited in relation to the amoebic dysentery connection nor the biologically plausible speculation of Professor Kune amount to more than this.

...

The appellant's appeal from the Tribunal's decision to a judge of this Court was dismissed. The learned primary
judge held that no error of law was contained in the Tribunal's decision.

As to Professor Kune's evidence on which the appellant relied to suggest a possible link between his amoebic dysentery and the development, 40 years later, of his cancer, the Tribunal concluded that that evidence was insufficient even to give rise to a hypothesis, let alone a reasonable hypothesis, connecting the cancer with the appellant's war-caused dysentery. In reaching this conclusion, it noted that the cases the subject of the two articles referred to by the Professor involved persons with ongoing serious inflammation of the bowel (due to parasitic infection) when they developed their cancers, while there was a latency period of 40 years between the infection suffered by the appellant and the development of his cancer. The Tribunal observed: "This alone would negative the application of the possibility referred to by the authors.".

To say that, in certain circumstances, bowel cancer may be connected with amoebic infection of the bowel cannot raise a hypothesis that the particular veteran's bowel cancer was connected with his war-caused bowel infection unless those same circumstances are present in the veteran's own case. In so far as Professor Kune's evidence, based as it was on the two medical articles, raised the suggestion of a possible connection, in the case of chronic sufferers, between their amoebic dysentery and the development of bowel cancer, that suggestion did not relate to this appellant's quite different circumstances: he was not a chronic sufferer, having only had the disease in the distant past. The Tribunal was, as the learned primary judge held, fully entitled to conclude that his evidence was insufficient to raise even a hypothesis that a link might exist between the two conditions from which the appellant had suffered. The Tribunal's decision here does not involve any reviewable error of law.

I have already set out the passage from the Tribunal's reasons in which it explained why it was not prepared to hold that Professor Kune's evidence raised a reasonable hypothesis connecting the appellant's irritable bowel syndrome with his cancer. There is nothing in the Tribunal's reasons suggesting that it did not accept what Professor Kune had to say. Essentially, the Tribunal considered that his evidence was insufficient to raise a reasonable hypothesis because he was unable to point to any literature to support it and because he could go no further than saying that a possible connection was plausible and worth further investigation. The learned primary judge held the Tribunal was right in reaching this conclusion.

Professor Kune was not prepared to express the opinion that the appellant's cancer was connected to his irritable bowel syndrome. The reason for his reticence here is clear: he said that "up to the present time there have been no systematic studies to either confirm or deny" the
possible existence of such a connection and that "there are just no data available, either to confirm or to deny this suggestion". But, notwithstanding this absence of proof, Professor Kune was still prepared to express the opinion that if there was an association between the two conditions (something he would accept only once that was established by data not presently available) then there was a "biologically plausible" explanation (i.e., what the Professor regarded as an acceptable scientific theory) for how the cancer could be causally linked to the irritable bowel syndrome.

In ordinary speech the term "hypothesis" is commonly used to refer to a provisional supposition which accounts for known facts and which is put forward to guide investigation. It is the essence of a hypothesis, as that word is ordinarily used, that it is provisional: whether it is true or false will only be established by evidence accumulated and assessments of its validity carried out after the hypothesis has been put forward. That is the sense in which this Court considered the term was used in s. 120(3) of the Act in East v Repatriation Commission, supra, at 532. If Professor Kune had said, in terms, that while there is no data currently available to prove that cancer of the colon is linked with irritable bowel syndrome, there is good reason for suggesting that the appellant's cancer and his irritable bowel syndrome were connected, it would, I think, be clear that he was putting forward a hypothesis that this appellant's war-caused condition was connected with his cancer. In my opinion, this is exactly the proposition that the Professor advanced in his reports and in his oral evidence, although he put it in a different form of words: to say, as he did, that there is no proof yet available that there is a connection between two conditions, but, if there is in fact a link, then there is an acceptable scientific explanation for how that link could arise, is in my opinion to advance a hypothesis that the two conditions may be connected. The Tribunal said of Professor Kune's evidence "he had suggested a possible connection between an irritable bowel syndrome and carcinoma of the colon". It correctly understood the Professor to have suggested that, although there was no proof available, it was possible that there was a connection between the appellant's irritable bowel syndrome and his cancer. In my opinion, for the reasons given, this suggestion can only be regarded as a "hypothesis" that that connection might exist. Having correctly stated its understanding of the Professor's evidence on this matter, it was unreasonable, in the Wednesbury sense, for the Tribunal then to hold that the Professor's "suggestion" could not be called a "hypothesis". But this error would be of no moment if the material before the Tribunal was insufficient to require a conclusion that it was a "reasonable hypothesis" within s. 120(3) of the Act.

Guidance on whether the requirement of reasonableness is satisfied is provided by Bushell where the Chief Justice and Deane and McHugh JJ said, at 414-415:

"The material will raise a reasonable hypothesis within the meaning of s. 120(3) if the material points to some fact or facts ("the raised facts") which support the hypothesis and if the hypothesis can be regarded as reasonable if the raised facts are true. Clearly enough, a relevant consideration in forming an opinion whether a particular hypothesis is reasonable is whether, as a matter of common or medical experience, the occurrence of an injury etc. of the kind sustained by the veteran is commonly accompanied by or associated with the occurrence of raised facts of the kind which constitute the relevant incidents of the service of the veteran. However, a hypothesis may still be reasonable even though such an accompaniment or association is not demonstrated or even if it is shown to be uncommon. So, in determining whether a hypothesis is reasonable for the purpose of s. 120(3), it is not decisive that a connexion has not been proved between the kind of injury which occurred and circumstances of the kind which constitute the relevant incidents of the veteran's service. Nor is it decisive that the medical or scientific opinion which supports the hypothesis has little support in the medical profession or among scientists.

...

However, a hypothesis cannot be reasonable if it is "contrary to proved scientific facts or to the known phenomena of nature". Nor can it be reasonable if it is "obviously fanciful, impossible, incredible or not tenable or too remote or too tenuous".

But leaving aside cases of those kinds, the case must be rare where it can be said that a hypothesis, based on the raised facts, is unreasonable when it is put forward by a medical practitioner who is eminent in the relevant field of knowledge."

Their Honours, in the course of considering how the Repatriation Commission should deal with conflicting medical opinions when deciding whether a reasonable hypothesis within s. 120(3) of the Act was raised, also said, at 415:

"... But it is vital that the Commission keep in mind that that hypothesis [that there is a connection between the incapacity or death and the
service of a veteran] may still be reasonable although it is unproved and opposed to the weight of informed opinion."

Proof to any level of probability of a connection between a medical condition and the veteran's war service is not a requirement of a reasonable hypothesis that such a connection exists. It is enough for such a hypothesis to arise for there to be a theory, unproven, but supported by facts raised by the material, that this is or may be the case. That there was, as Professor Kune explained, no proof yet available of a connection between bowel cancer and irritable bowel syndrome cannot prevent his suggestion constituting a reasonable hypothesis that such a connection might exist in this case.

I also think that it is enough for there to be a reasonable hypothesis within s. 120(3) of the Act if there is a sufficiently acceptable hypothesis that the veteran's war service and his disease might be connected: it is not necessary that the hypothesis goes so far as to assert that there is such a connection. Section 120(1) of the Act requires the Repatriation Commission to determine that a disease was war-caused unless it is satisfied, beyond reasonable doubt, that there is no sufficient ground for making that determination. If the material before the Repatriation Commission raises a reasonable hypothesis that the particular veteran's disease might be (rather than is) connected with his war service, such a hypothesis must
necessarily create a doubt that is a reasonable one as to whether the requisite connection exists. Unless that doubt is removed, s. 120(1) of the Act obliges the Repatriation Commission to determine that the requisite connection does exist.

In my opinion, Professor Kune's evidence, when read with certain other evidence in the case, constituted material that satisfied the requirement, identified in Bushell, at 414, and explained in Byrnes, at 569, that it "points to some fact or facts (`the raised facts') which support the hypothesis" that there was a connection between the appellant's irritable bowel syndrome and his cancer which, if true, are sufficient to demonstrate the reasonableness of that hypothesis. His opinion was that the conditions he believed were associated with the appellant's irritable bowel syndrome could have produced a condition of hyperplasia which is known to be causally connected with cancers occurring in other parts of the body, especially when the condition of hyperplasia is longstanding. That is enough to raise a hypothesis that the appellant's irritable bowel syndrome and his colonic cancer were or at least might be connected: that was the whole purport of the Professor's evidence here. His evidence and that of the appellant pointed to the following "facts" which supported this hypothesis:

(a) the appellant suffered from his irritable bowel syndrome for a very long period of time

(b) the appellant on many occasions was forced to pass motions up to eight times a day

(c) his irritable bowel syndrome was, according to Professor Kune, associated with "an excessive production of mucus and fluid ..."

(d) the excessive production of mucus and fluid in the bowel could be accompanied by hyperplasia, i.e., hyperactivity of the lining cells of the bowel

(e) some cancers, other than bowel cancers, are known to be causally linked to hyperactivity in cell behaviour. Professor Kune said: "... what we see with other cancers when there is excessive functioning, hyperplasia, there is an increased risk of a cancer developing at that site ... This is a general concept that we have evidence for, for many different cancers around the body."

(f) the longer this hyperactivity persists, the greater is the chance of a cancer developing.

The Tribunal accepted (a) and (b) as true. Professor Kune gave evidence which, if accepted, showed that (c), (e) and (f) were also established truths. As the
Professor himself acknowledged, (d) was not proven, but was a matter of supposition on his part. However, that a hypothesis assumes the existence of a "fact" does not of itself make the hypothesis unreasonable: Byrnes, at 570. The supposition that cell hyperactivity existed was part of the hypothesis and it was not a matter for proof or evidence: Byrnes, at 571-572.

This material I have set out above was sufficient to show that Professor Kune's hypothesis was a reasonable one. Dr. Levi did not dispute what Professor Kune had to say about hyperplasia having a known association with cancers in various parts of the body. There is nothing about this hypothesis that I can see which marks it as "obviously fanciful". It is put forward by an expert who is eminent in the relevant field of knowledge. In East v Repatriation Commission, supra, a decision cited with approval by the High Court in Bushell, this Court reviewed the history of s. 120 of the Act and concluded that, by enacting s. 120 in the 1986 Act:

"... Parliament was requiring something by way of causal link, but which fell short of proof of the link - even prima facie - as a fact."

The Full Court approved the explanation of the phrase "reasonable hypothesis" in s. 120(3) of the Act given by the Veterans' Review Board in Stacey, in words quoted by the Tribunal in Re Dell and Repatriation Commission (1986) 9 A.L.D. 596 at 615, in the course of which the Board said:

"Accordingly a connection asserted by a hypothesis to exist between death or incapacity and service may still be reasonable, even though theoretical, and it may be theoretical in either or both of at least two senses: by postulating a known medical fact but in circumstances not known to have definitely existed in the instant case; or by postulating a medical principle which science is not yet able to definitely prove but is unable to describe as unreasonable."

Professor Kune's hypothesis postulated that the appellant's war-caused bowel problem may have led to the development of hyperplasia, a condition known to result sometimes in cancer. The existence of this condition of hyperplasia and thus the connection that Professor Kune suggested may in turn exist between the appellant's bowel condition and his cancer were unproven and theoretical; but the connection was still one reasonably hypothesised to exist. As the Court in Bushell observed, at 414-415, absent a case in which the hypothesis is obviously fanciful, impossible, incredible or not tenable or too remote or too tenuous and absent a case in which the hypothesis is contrary to proved scientific facts or to the known phenomena of nature, the case must be rare where it can be said that a hypothesis, based on the raised facts, is unreasonable where it is put forward by a medical practitioner who is eminent in the relevant field of knowledge, as Professor Kune undoubtedly is.

Professor Kune's evidence did not, as the Tribunal considered to be the case, raise only a mere possibility that left open, but did not point to, there being a connection between this appellant's war-caused disease and his cancer. His evidence here differed significantly in effect from his evidence concerning the relationship between the appellant's amoebic dysentery and his bowel cancer. It focused on this appellant's circumstances and put forward a suggestion that his war-caused condition may, because of its chronic nature, ultimately have led to a condition of hyperplasia known to be causally related to cancer in other parts of the body. His evidence showed in this way how this particular appellant's war-caused disease may have been connected with his cancer. If every essential fact he spoke about which supported his theory is assumed to be established, an assumption that must be made when the application of s. 120(3) of the Act is under consideration, Professor Kune's evidence does not merely leave open, as an unresolved issue, whether that connection between this appellant's irritable bowel syndrome and his cancer existed or might have existed: instead, it points affirmatively to the existence of a possible connection.

But for Dr. Levi's evidence concerning the villous adenoma upon which the Tribunal also relied to dismiss the appellant's claim, the Tribunal, having accepted Professor Kune's evidence about the appellant's irritable bowel syndrome, would, in my opinion, have been bound to hold that his evidence raised a reasonable hypothesis that the appellant's irritable bowel syndrome and his cancer were connected.

I turn now to the second question in the appeal which is concerned with the use made by the Tribunal of Dr. Levi's testimony. He attached great significance to the evidence that the appellant's cancer was associated with a villous adenoma. The Tribunal accepted what Dr. Levi said as showing that the appellant's cancer was genetic in origin and was wholly unrelated to either his amoebic dysentery or his irritable bowel. The Tribunal then resolved the case by stating, in words taken from s. 120(1) of the Act, that it was satisfied beyond reasonable doubt that the appellant's cancer was not war-caused because the evidence did not raise a reasonable hypothesis to the contrary. But the Tribunal reached this last conclusion by deciding, firstly, that Professor Kune's suggestions could not amount to a hypothesis and, secondly, even if one or both of those suggestions did amount to a hypothesis, it was not a reasonable one because it was "contrary to the known and established cause of" the cancer. I agree with the learned primary judge that the Tribunal disposed of the case under s. 120(3) of the Act. As the passage from Byrnes, at 571, quoted by the Tribunal, shows, it was unnecessary (even though it did so) for the Tribunal to turn to s. 120(1) of the Act and consider whether it was satisfied beyond reasonable doubt that there was no sufficient ground for determining that the cancer was war-caused, since it had concluded, in performing the task required by s. 120(3) of the Act, that the evidence did not raise the necessary reasonable hypothesis.

The learned primary judge agreed with the Tribunal's first reason for dismissing the case under s. 120(3) of the Act, viz., that no hypothesis was raised; it was thus unnecessary for him to consider whether the Tribunal's dismissal of the case was justified on the second ground that it gave. Since I consider that Professor Kune's evidence did raise a hypothesis connecting the appellant's irritable bowel with his cancer, the Tribunal's decision cannot stand unless it was entitled to dismiss the appellant's case on the second ground it put forward for holding that the appellant had to fail in passing the s. 120(3) barrier, viz., that "in any event", that is, even if the Tribunal was wrong and a hypothesis was raised by the evidence, it was still not a reasonable one because it was "contrary to the known and established cause of the condition".

It is only if the Tribunal was entitled to treat Dr. Levi's evidence that the cancer was genetic in origin as based upon established scientific fact within the dicta in Bushell, at 414, and Byrnes, at 570, that the Tribunal could properly dismiss the case under s. 120(3) of the Act, on the second ground which it gave. In Bushell the Court, at 414, said: "... a hypothesis cannot be reasonable if it is `contrary to proved scientific facts or to the known phenomena of nature'. Nor can it be reasonable if it is `obviously fanciful, impossible, incredible or not tenable or too remote or too tenuous'". In Byrnes, at 571, the Court recast this statement in the following terms: "The hypothesis will not be reasonable if it is contrary to known scientific facts or is obviously fanciful or untenable. If the hypothesis is not reasonable, the claim fails. Proof of facts is not an issue at this point." In my opinion, in stating the principle in this form, the Court was making it clear that a hypothesis will lack rationality because of conflict with established principle only where it conflicts with a scientific principle or fact so widely recognised as true that the principle or fact need not be proved by evidence, but is able to be acknowledged by the Court taking notice of it.

I do not think that the Court in Bushell and Byrnes regarded a "known scientific fact" as a matter generally, but not universally, accepted as true by the relevant scientific community. A tribunal could not take judicial notice of such matters of scientific knowledge, but could act on them only once they were properly proved by evidence. But Bushell and Byrnes show that it is no part of the Tribunal's function, when it is considering s. 120(3) of the Act, to resolve conflicts of expert opinion or other evidence: that is a function reserved for when the Tribunal gets past s. 120(3) the Act and has to consider the application of s. 120(1) of the Act to the particular case. The High Court said in Bushell, at 415, that a hypothesis could be a reasonable one sufficient for the purposes of s. 120(3) of the Act even though "it is unproved and opposed to the weight of informed opinion" and in Byrnes, at 569, that "it is not decisive that a medical opinion that supports a hypothesis `has little support in the medical profession or among scientists' ...". This is another reason why an opinion that conforms to a generally, but not universally, accepted medical view cannot be capable of reflecting a "known scientific fact" so as to be sufficient to destroy the force of an inconsistent opinion that supports the hypothesis relied on by the veteran. Moreover, the collocation of the expression "proved scientific fact" with "obviously fanciful, impossible, incredible" in the list of descriptions of hypotheses incapable of being regarded as reasonable ones in the statement in Bushell, at 414, also suggests that the Court there was referring, by the expression "contrary to proved scientific facts", to a hypothesis so lacking in credence that evidence proving that it was erroneous was unnecessary. That this is what the Court in Bushell meant is, I think, confirmed by the High Court's comment in Byrnes, at 571, that when s. 120(3) of the Act is under consideration, "[p]roof of facts is not in issue at this point".

I therefore consider that a fact will be a "proved" or a "known scientific fact" in the sense in which those expressions are used in Bushell and Byrnes only if it is so notorious as to be the subject of judicial notice at common law or a fact of the kind covered by s. 144 the Evidence Act 1995 (Cth), i.e., a fact not reasonably open to question and which thus need not be proved by evidence.

There is a range, albeit limited, of medical facts of which a Court can take judicial notice at common law because they are so generally known and accepted that even an ordinary person will be presumed to be aware of them. That the blood circulates from the heart through the arteries and veins back to the heart is such a notorious fact. Section 144 the Evidence Act 1995 (Cth) may well permit the Court to have regard to a wider range of medical facts than are judicially noticeable at common law. That tuberculosis is caused by the tubercle bacillus and that malaria is caused by organisms injected by the bites of certain species of anopheles mosquitoes are probably facts which a court could accept as true without proof, pursuant to s. 144 the Evidence Act 1995 (Cth), even if it could not judicially notice those facts at common law. But if information were produced to the Tribunal that was apparently worthy of some credence and which denied the truth even of such "facts", s. 144 the Evidence Act 1995 (Cth) would, I think, be revealed thereby not to be applicable to those "facts". They would then have to be proved to be true by evidence in the same way as any ordinary contested factual issue is resolved. Cf. Horman v Bingham [1972] V.R. 29 at 34.

I do not think that Dr. Levi's evidence that, because the appellant's cancer had arisen in association with a villous adenoma, the cancer was genetic in origin and therefore unrelated to the appellant's bowel problems can be regarded as referring to a proved or known scientific fact
sufficient of itself to prevent Professor Kune's hypothesis from being accepted as a reasonable hypothesis. Dr. Levi's evidence was that the villous adenoma provides "a very definite indication of what the likely factor was in the development of" the appellant's cancer; that "villous adenomas are well known to be developmental conditions that arise usually in people with a genetic predisposition to them", and "of all the different types of adenomas villous adenomas are the ones with the highest pre-malignant predisposition". What Dr. Levi's evidence established, if accepted, was that current scientific knowledge showed, to a high level of probability, what was the cause of the appellant's cancer. He was speaking about far too technical matters than could be noticed by a court, without proof. The fact that his opinion was qualified, even though only in a limited way, also shows that he was not testifying about a "known scientific fact", only as to his opinion that the cause of the cancer was quite different from that hypothesised by Professor Kune and why he could express that opinion with a high degree of confidence as to it being correct. The Tribunal was in my opinion in error in acting on Dr. Levi's evidence to conclude that even if what Professor Kune said was sufficient to raise a hypothesis within s. 120(3) of the Act, any such hypothesis was not a reasonable one. The Tribunal was in truth then faced with a typical conflict between two medical experts as to the possible cause of the cancer, which it could only resolve when it came to consider s. 120(1) of the Act.

For the reasons given, the Tribunal was in error in dismissing the appellant's application for review. It is unfortunate that the case cannot be finally disposed of by this Court but must, in my opinion, go back to the Tribunal for further consideration. This result follows for these reasons: the Tribunal found that no reasonable hypothesis connecting the cancer with the appellant's war service within s. 120(3) of the Act was raised. So the only course open to it, when it went on to consider s. 120(1) of the Act (even though it was unnecessary for it to do that), was to find that it was satisfied beyond reasonable doubt that there was no sufficient ground for determining that the cancer was war-caused. It had to reach this last conclusion, whether it accepted Dr. Levi's evidence as showing the cause of the cancer beyond reasonable doubt or only according to a lesser standard of proof. I do not think it is possible to know just what standard of persuasion the Tribunal reached in accepting Dr. Levi's evidence: its reference to Dr. Levi making "the telling point that the evidence ... identifying a villous adenoma, would be conclusive of the cause of the applicant's cancer" cannot be assumed to be a finding that the cause of the cancer was proved to the Tribunal's satisfaction beyond reasonable doubt (rather than to some lesser standard of persuasion). Moreover, there is reason for thinking that even if it did reach such a high level of persuasion as to the actual cause of the cancer, it ignored evidence to the contrary in doing so: it was submitted on behalf of the appellant that it should be inferred that Professor Kune was aware that the appellant's cancer was associated with a villous adenoma but that he did not consider this of sufficient significance to be worthy of comment. I accept this submission. It is highly unlikely, in view of the exchange between Admiral Leach, a Tribunal member, and Professor Kune, to which counsel for the appellant referred, and in view of what the Professor had to say in his report of 9 November, 1992, that he was ignorant of the pathology findings concerning the villous adenoma. The proper conclusion to be drawn from the absence of any reference by the Tribunal in its reasons to Professor Kune's apparent position on this matter may well be that it failed to take into account that Professor Kune was aware of the pathological evidence as to the villous adenoma on which Dr. Levi relied in giving his opinion as to the cause of the cancer, but considered it was of no relevance to the aetiology of the appellant's cancer: cf. s. 43(2) the Administrative Appeals Tribunal Act 1975 (Cth) and Arm Constructions Pty. Ltd. v Commissioner of Taxation (1986) 10 F.C.R. 197 at 205. It is thus a matter of speculation as to what conclusion the Tribunal would have reached if it had held, as it should have, that Professor Kune's evidence raised a reasonable hypothesis connecting the appellant's cancer with his war service and then went on to consider the issue that would then have arisen for determination under s. 120(1) of the Act.

Moreover, Professor Kune's reasons for apparently thinking that the villous adenoma was of no significance were never elicited: the respondent adduced Dr. Levi's opinion to the contrary without prior notice and without having put it to Professor Kune for comment when he was in the witness box and the appellant then failed to take any action to procure Professor Kune's views on this question. This Court is therefore not in a position, in the absence of knowing Professor Kune's views, to assess whether his evidence would be sufficient to prevent the Tribunal properly concluding beyond reasonable doubt, for the purposes of s. 120(1) of the Act, that there was no sufficient ground for determining that the cancer was war-caused when it came to perform the task imposed on it by s. 120(1) of the Act.

There is therefore no ground for concluding that the Tribunal's error of law in failing to find that a reasonable hypothesis was raised was only an immaterial error of law of the kind that does not vitiate a decision of the Tribunal. Cf. BTR PLC v Westinghouse Brake & Signal Co. (Australia) Ltd. (1992) 106 A.L.R. 35 at 41-42.

I would therefore allow the appeal, set aside both the decision appealed from and the decision of the Tribunal and remit the case to the Tribunal to be heard again. The Tribunal should be at liberty to receive further evidence.

I certify that this and the preceding

25 pages are a true copy of the reasons

for judgment herein of the Honourable

Justice Drummond.

Associate:

Date: 27 September 1995

Counsel for the appellant: M. Maurice QC

Solicitors for the appellant: Legal Aid Commission of NSW

Counsel for the respondent: Mr D.E.J. Ryan

Solicitor for the respondent: Australian Government Solicitor

Date of hearing: 22 May 1995

Date of judgment: 27 September 1995

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