Federal Court of Australia

Save Wallum Incorporated v Clarence Property Corporation Limited (No 4) [2025] FCA 389

ORDERS

THE COURT ORDERS THAT:

1.    Leave to re-open the evidential ruling made on 28 February 2025 excluding the opinion evidence of David Milledge is granted.

2.    The evidential ruling made on 28 February 2025 excluding the opinion evidence of Mr Milledge is set aside under rule 39.04 of the Federal Court Rules 2011 (Cth).

3.    Costs of the interlocutory application to set aside the evidentiary ruling made on 28 February 2024 are reserved.

THE COURT NOTES THAT:

4.    The parties are to confer with a view to resolving the remaining objections to Mr Milledge’s expert reports by agreement if possible and otherwise as to the time at which, and the most efficient means by which, any remaining objections are to be resolved by the Court.

Note:    Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.

REASONS FOR JUDGMENT

PERRY J:

1    INTRODUCTION

1    By way of background, the applicant seeks an injunction under s 475(2) of the Environment Protection and Biodiversity Conservation Act 1999 (Cth) (the EPBC Act) to restrain the first and second respondents from carrying out or authorising the carrying out of development works on the land at 15 Torakina Road, Brunswick Heads, NSW (the Land), subject to approval by the Commonwealth Minister for the Environment and Water under Part 9 of the EPBC Act, and slashing works on the Land.

2    The first and second respondents, Clarence Property Corporation Limited and Bayside Brunswick Pty Ltd, seek to develop the Land pursuant to a development approval issued by the Northern Regional Planning Panel. On 16 May 2023, the Planning Panel granted approval for the respondents to create 123 residential lots, 3 medium density lots, and 1 public reserve, together with associated vegetation management works, earthworks and construction of infrastructure, in 7 stages subject to various conditions (the Development).

3    The applicant contends that the Development is likely to have a significant impact on various listed threatened species under the EPBC Act, namely:

(1)    the Wallum Sedge Frog (WSF), the Long-nosed Potoroo (LNP) and the South-eastern Glossy Black-Cockatoo (SEGBC) which are in the vulnerable category under the EPBC Act;

(2)    the Koala which is in the endangered category under the EPBC Act; and

(3)    the Mitchell’s Rainforest Snail (MRS) which is in the critically endangered category under the EPBC Act.

(Together, the relevant listed threatened species.)

4    This matter involves a very substantial body of expert evidence addressing, among other things, the potential impact, if any, on each of the relevant listed threatened species and whether there is a significant population of each species on the Land. Experts on each of the relevant listed threatened species prepared individual reports and, in some cases, multiple reports, prior to the trial. Each group of experts also participated in an expert conclave without the presence of the parties or their legal representatives and produced a joint expert report in which areas of agreement and disagreement were identified.

5    This matter is now part-heard with concurrent expert evidence having been given by the hydrological and hydrogeological experts and experts in relation to the WSF. Relevantly, the remaining expert evidence is listed for cross-examination in concurrent sessions for the week commencing 28 April 2025.

6    The expert witnesses for the applicant include David Milledge who is a consultant wildlife ecologist. Mr Milledge prepared four reports altogether for these proceedings, focusing on the LNP in his first report dated 30 July 2024, the SEGBC and Koala in his second report dated 12 August 2024, the LNP and Koala in his third report dated 23 September 2024, and the LNP in his fourth report dated 9 January 2025. Mr Milledge also contributed to the joint expert reports on these species.

7    I do not understand that Mr Milledge’s extensive expertise with respect to these species, and in particular with respect to the LNP, is in dispute, at least at this stage. The applicant also relies upon the expert evidence of Associate Professor Grant Wardell-Johnson, among others, who gives evidence on all of the relevant listed threatened species.

8    Mr Milledge was individually cross-examined by the respondents on 28 February 2025 on matters relevant to his independence, impartiality and objectivity in light of prior activities undertaken by him opposing the Development. At the end of that cross-examination, on the respondent’s application, I ruled that Mr Milledge’s opinion evidence was not admissible (the Ruling). However, the Ruling did not extend to evidence given by him of matters of fact. For example, evidence that he took photographs of diggings on a particular day, and evidence that he took those photographs because he believed that the diggings were by a LNP, were not excluded by the Ruling. However, consistently with the Ruling, evidence that, in his opinion, the diggings were likely made by a LNP was excluded.

9    I also made consequential orders by consent on 14 March 2025 to give effect to the Ruling that the parties were to agree on and file a schedule of evidence to be struck out arising from the Ruling made on 28 February 2025.

10    The applicant seeks orders under r 39.04 of the Federal Court Rules 2011 (Cth) (the FCR) to set aside the Ruling excluding the opinion evidence of Mr Milledge. Rule 39.04 provides that “[t]he Court may vary or set aside a judgement or order before it has been entered”. The applicant accepts that the discretion to set aside the Ruling should be exercised “with great caution” having regard to the importance of the public interest in the finality of litigation: Autodesk Inc v Dyason (No 2) (1993) 176 CLR 300 at 302 (Mason CJ). However, in the applicant’s submission, the Ruling was made under a misapprehension of the law by reason of the parties not having drawn relevant authority to the attention of the Court, and, relatedly, the interests of justice require that the Ruling be set aside.

11    For the reasons set out below and not withstanding Ms Davidson’s thorough and compelling arguments for the respondents, I consider that the Ruling was made under a misapprehension of law or at least an incomplete appreciation of the applicable legal principles. I further consider that leave to re-open the Ruling should be granted, and that the Ruling should be set aside under r 39.04 of the FCR. Subject to ruling on specific objections to Mr Milledge’s expert opinions and other evidence as foreshadowed by the respondents, his expert opinion evidence should be admitted. Questions as to the weight, if any, to be afforded to Mr Milledge’s opinion evidence in light of his evidence in cross-examination on the voir dire and otherwise in concurrent session will no doubt be the subject of submissions in due course.

12    Finally, any views which I express with respect to Mr Milledge’s capacity to give independent, impartial and objective opinion evidence and otherwise as to his evidence are made solely in the context of determining the interlocutory application. Given that he has not yet given his evidence in concurrent session, these views are necessarily preliminary in nature.

2    CROSS-EXAMINATION OF MR MILLEDGE

13    The most salient aspects of Mr Milledge’s evidence in cross-examination can be summarised as follows.

(1)    Mr Milledge had visited the Land on a couple of occasions undertaking assessment and compliance tasks in respect of the Land. These tasks were part of his duties when he was employed by the Byron Shire Council in the role of Ecologist – Environmental Services between 2005-2008.

(2)    Before he was retained by the applicant, Mr Milledge made an unpublished internal report to his director in 2006 in respect of the site (the 2006 report). Mr Milledge also made an unpublished submission in 2011 on his own account as an ecologist to the NSW Department of Planning and Infrastructure in which he advocated for the concept plan for the proposed development of the Land to be refused (the 2011 submission). He accepted that his involvement in preparing these documents was directly relevant to an assessment of the impartiality of his evidence in this proceeding. Mr Milledge was asked in cross-examination why these matters had not been expressly referred to in his first expert report in answer to the question requesting “brief information” as to his experience and qualifications relevant to the subject of his brief. In response, Mr Milledge pointed to references to the 2006 report and 2011 submission in the references attached to his first report in this proceeding.

(3)    Mr Milledge sent a letter on or about 23 October 2023 directly to the Minister, submitting that the development application by the respondents over the Land should be “call[ed] … in for referral”. In that letter, he referred to his long association with the Land and submitted that he had dealt with “constant and cumulative destruction and degradation of threatened species’ habitat there by tractor slashing” in his capacity with the Council. He made the submission to the Minister at the applicant’s request although that was not stated in the letter.

(4)    Mr Milledge sent a further letter to the Minister on 17 November 2023 again at the applicant’s request. In this letter, he stated that there would be “permanent destruction of approximately 5ha of foraging habitat for the Vulnerable Grey-headed Flying-fox” and asked the Minister to “ensure that the important areas of the species’ flowering tree and shrub food resource in the site, together with linking areas currently being slashed, are considered and protected under any referral of impacts made to your Department”.

(5)    Mr Milledge accepted in retrospect that he should have included in his expert report and/or his curriculum vitae that he had written under his own hand to the Minister twice objecting to the Development because it was relevant to his ability to give impartial evidence to the Court. He also accepted that these letters showed a firm opposition to the Development on a number of different grounds “stemming from my involvement with the site and the proposal while I was working for Byron Council” and that they involved his direct advocacy to the Minister against the carrying out of the proposed development on behalf of the applicant. He did not have an explanation for why the letters had not been disclosed except for stating “that the material contained in those letters is all contained within previous correspondence and in my reports”.

(6)    Mr Milledge prepared a submission on or around 30 January 2024 for the applicant that was submitted to a Council meeting by the applicant. Mr Milledge thought that he may have also sent a copy of that submission to the editor of the newspaper, The Byron Echo, and to the mayor. He accepted that his purpose in preparing the submission was to advance arguments as to why the Council should not proceed with the release of the subdivision certificate for the first stage of the Development and that it was a letter in opposition to the Development continuing. He explained that, while he may have been advocating on behalf of the applicant, he considered that he was “advocating on behalf of the threatened species… [a]s a conservation ecologist”. He also accepted that he raised a number of reasons in this submission as to why the Development should not proceed, including the economic cost to the Council of the Development proceeding and alleged breaches of the concept approval conditions and the development approval conditions. He also agreed with the proposition that he was putting forward everything he could think of to try and get the Development stopped and was doing so expressly at the request of the applicant. In that submission, he stated that “[a] total of 19 threatened fauna species … have been recorded in the site, with another two highly likely to occur. The development will destroy important habitat, and in most cases known habitat of 13 of these species”. He accepted that one of the species mentioned was the LNP. He also accepted that he did not disclose this submission in his first expert report but agreed that he should have done so in retrospect. Furthermore, he accepted that the submission showed that he was “implacably opposed to this development in 2023 and 2024” although he did not agree that he would pursue that opposition by any means whatsoever.

(7)    Mr Milledge agreed with the proposition that when he prepared his expert reports for these proceedings, he regarded that as “another opportunity to put forward an explanation as to why the development should not go ahead”. In answer to the question whether, throughout preparation of his written evidence including the joint expert report, he remained implacably opposed to the Development, he said that:

[w]ell, when we – when we were discussing the issues in the joint conference, it was simply in relation to the facts rather than any particular position I might have taken.

The joint expert reports, however, disclose that the experts identified significant differences of view about matters such as the presence of the LNP on the Land during their discussions in conclave.

(8)    Mr Milledge prepared a critique dated 5 February 2024 of the amended plans for the development application. He provided the critique at the mayor’s request “[a]s a basis for negotiation, I think, if I remember” and the mayor, in turn, presented the critique at the Council meeting of 8 February 2024.

(9)    Mr Milledge accepted that he spoke to the media “[m]aybe only once or twice” about the development site and that he was interviewed by Stephanie Smail from the Australian Broadcasting Corporation (ABC) on or about 12 February 2024 about the Development.

(10)    As reported in an article published in The Byron Echo on 10 April 2024, Mr Milledge remembered telling a journalist that the artificial frog ponds (which are part of the Development) were “pointless”. He also accepted that he could have said to the journalist that “the developer appears to be ignoring the major community opposition to the development and a complete lack of any social licence”, and agreed that he said that “[t]he development site plan as approved will be a disaster for biodiversity”.

(11)    Mr Milledge accepted, as recorded in an article published by The Byron Echo on 25 April 2024, that he had described the three councillors’ concessions referred to in the article as “ineffective”. He also accepted that this “was another occasion [on which he was] speaking to the media in the context of providing reasons for opposing the development at the development site”.

(12)    Mr Milledge gave evidence in re-examination that he was not motivated as such by a desire to assist the applicant as an organisation in themselves, but that his “main desire was to see that the threatened species received some protection”.

3    THE RULING

14    Given that it is said that the Ruling with respect to Mr Milledge’s opinion evidence was based on a misapprehension of the law, it is necessary to set out the parties’ respective submissions and the reasons given for the Ruling.

15    Following the cross-examination, Mr Lancaster SC, counsel for the respondents, submitted that Mr Milledge’s expert opinion should not be received as “[h]e has contravened in the most explicit way both the letter and the purpose of the expert witness code of conduct by literally acting as an advocate for the party, the applicant”. Mr Lancaster SC further submitted that:

Your Honour can have no basis to expect impartial assistance from this witness, having regard to his consistent advocacy proceedings – advocacy against the development that are subject of the proceedings. As we’ve seen directly to the Commonwealth Minister, the New South Wales Department of Planning, to local media, to national media, he has just put himself in a position where his obvious partiality is, in my submission, disqualifying of his capacity to provide the expected impartial assistance of an expert to the court that is required, and indeed agreed to, by the expert pursuant to the Code. And he wrote in his own name. He said on various occasions that some of them were at the request of Save Wallum or their principals, Mr Barry and others. It’s clear that his partiality is extreme. And when I invited him to explain why it wasn’t in his report, he provided no explanation.

…

[I]n my submission, he has disqualified himself from the role of an expert in this court.

16    Mr Korman, counsel for the applicant, pressed for receipt of Mr Milledge’s opinion evidence, submitting that, while an expert, having judged the facts carefully and impartially, might conclude that serious environmental damage may occur, that does not necessarily mean that the expert is biased even if the expert shares very strong feelings on the subject. Similarly, Mr Korman submitted that being partial and even agitating for a certain environmental outcome does not in and of itself disqualify an expert. In his submission, while in the past Mr Milledge took actions on behalf of the applicant, those actions do not mean: (1) that, in his role as an expert witness, he had not read the Harmonised Expert Witness Code of Conduct; (2) that he was not prepared to make concessions where they ought to be made; and (3) that he was not going to look at the facts in an impartial sense “as any other scientist would in his shoes”. The following exchange then took place:

HER HONOUR: Well, I’ve indicated to Mr Lancaster that he wouldn’t necessarily have to go so far as to invite me to make a positive finding of a breach of the Expert Code of Conduct. But what is troubling my mind is, you know, even fully accepting – and I think, in his evidence, he was very genuine and he was prepared to accept where he had made mistakes, I think his evidence to the court came across as being very honest and well-meaning. But the difficulty that I see if I can raise it with you so that I get the benefit of your submissions, is that he clearly has acted as an advocate and a very, very passionate advocate for what he believes is right and, in so doing, has, it would appear, lost either the objectivity required of an expert witness under the code of conduct or gives the appear[ance] of having lost that objectivity. So how is it then that the court would be able to give weight to his evidence and be – feel confident that he was able to make appropriate concessions?

MR KORMAN: Yes, your Honour. So my submission would be that, despite the fact that he had acted as he acted in the past, having accepted upon himself these duties, the duties of an expert witness, he has also accepted the duty to evaluate the facts and act impartially. I would submit that he is in – despite his actions, if one looks through them, he is in no position different to a researcher or scientist who has taken a certain view, has published extensively in support of that view, has passionately advocated for that view and, in this case, the view that there are threatened species on the site that would be affected.

HER HONOUR: Well, if I play devil’s advocate for a moment, has he not arguably gone beyond that because he has argued very passionately and using all of the – what he regards as proper means available to him to advocate positively against this development and in favour of its referral to the Commonwealth.

MR KORMAN: Yes, your Honour.

HER HONOUR: So I – it would seem to my mind, again playing devil’s advocate, that he has gone beyond the role of someone who may, in a theoretical sense, have published various papers expressing views on subjects that later become the subject – become relevant to proceedings.

MR KORMAN: Yes, your Honour. So, as I submitted, in relation to his actions on behalf of Save Wallum, my submission would be that, having become an expert witness, he has the ability to put that to one side and to act impartially and give impartial opinions to the court.

17    In reply, Mr Lancaster SC submitted that “[t]here is … nothing in the evidence that Mr Milledge gave” that could lead the Court “to be confident that he could provide the necessary impartial assessment”, given he has written directly to politicians and decision-makers at the State and Commonwealth level and talked to local and national media. The following exchange then took place:

HER HONOUR: Well, I fear too that even when often one tries very hard to comply —

MR LANCASTER: Yes.

HER HONOUR: — the biases or the very strong views that he clearly holds may influence him, even if subconsciously

MR LANCASTER: Yes.

HER HONOUR: — given the strength of his views and the facts —

MR LANCASTER: Yes, your Honour, that’s my submission. And it’s underscored by the content of the adverse submissions that he has made historically which, as your Honour say, ranged over a wide range —

HER HONOUR: A broad range.

MR LANCASTER: — of species, including species that are no part of these proceedings.

18    I then delivered my ruling as follows on the objection to Mr Milledge’s opinion evidence:

I’ve listened carefully to what has been said, and I understand that it’s difficult for the applicant, but I don’t consider that the evidence – in light of the evidence that has been given by Mr Milledge – can be received. It’s – I think my reasons have emerged sufficiently from the discussions with counsel around the issue, but I want to make it absolutely clear that, as I said, I accept Mr Milledge gave his evidence here today honestly, and I accept that. But I also accept he holds these views very passionately, but it has, unfortunately – through his conduct, he has placed himself in a position where the court cannot be confident that he can bring the necessarily objective mind to bear on the issues that is required of an expert witness under the Code of Conduct.

19    Subsequently, on 3 March 2025, I clarified the scope of the Ruling explaining that:

What has been excluded, because of the concerns of subconscious or conscious partiality, is the evidence of opinion – his opinion …

But if he has – if he gives evidence, “I took a photograph on a particular day with my iPhone. I’ve attached the photograph, which has the date and time and location marked on it,” I would have thought that that evidence would be able to go in consistently with my ruling. But what wouldn’t then be able to go in as well is his opinion as to what that photograph depicted.

…

You remember the ruling the – we made with respect to the lay evidence – that we allowed their evidence as to what it was that they thought they had identified, as evidence of the reason why they took the photograph, but not as evidence of their opinion of what the photograph depicted?

… It would be the same limitation, logically, that would apply to his. Because, effectively, what we are then doing now is, we are treating his evidence as the evidence … of a lay person.

20    Junior counsel for the respondents, Ms Davidson, agreed that this was consistent with the Ruling.

4    DISPOSITION OF THE APPLICATION

4.1    Relevant principles: discretion to set aside

21    The relevant principles with respect to the exercise of discretion under r 39.04 of the FCR were summarised in Ashby v Slipper (No 2) [2014] FCAFC 67 at [13]-[15] (the Court (Mansfield, Siopis and Gilmour JJ)):

The exercise of the discretion to vary or set aside orders, including under r 39.04 FCR, is a power to be used only sparingly, with great caution and rarely, having regard to the public interest in the finality of litigation: Autodesk Inc. v Dyason [No 2] (1993) 176 CLR 300 at 302; Grimaldi v Chameleon Mining NL (No 2) (2012) 200 FCR 296 at [772]; and see generally Wenkart v Pantzer (No 3) [2013] FCAFC 162.

The discretion is exercised to cure injustice, particularly where it would otherwise be irremediable: see, e.g., De L v Director-General, New South Wales Department of Community Services (1997) 190 CLR 207 at 215. Grounds upon which a variation can be made are varied: see, e.g., Maritime Union of Australia v Geraldton Port Authority (2001) 111 FCR 434 at [20]. They include error, oversight, a misapprehension of the law, or a decision given in ignorance or forgetfulness of a statutory provision.

As Kenny J stated in Inspector-General in Bankruptcy v Bradshaw [2006] FCA 22 at [24]: “[i]n every case the overriding principle to be applied is whether the interests of justice are better served by allowing or rejecting the application for leave to re-open”: see also The Silver Fox Company Pty Ltd as Trustee for the Baker Family Trust v Lenard’s Pty Ltd (No 2) [2004] FCA 1310 at [22] per Mansfield J; Blank v Commissioner of Taxation (No 2) [2014] FCA 517 per Edmonds J.

4.2    Was an error of law made?

4.2.1    The parties’ submissions

22    The applicant contends that the Court should grant leave to reopen the Ruling and exercise its discretion under r 39.04 of the FCR to set aside the Ruling on the basis that the Court proceeded on a misapprehension of the law as set out in the decision in Rush v Nationwide News Pty Limited (No 5) [2018] FCA 1622 which was not drawn to the Court’s attention at the time of the Ruling.

23    In the applicant’s submission, that decision established that “actual or perceived lack of independence, impartiality or objectivity of an expert witness goes to weight, not admissibility”. In the applicant’s submission, if the criteria in s 79 of the Evidence Act 1995 (Cth) are satisfied, the Court does not have power to exclude the expert opinion evidence subject to the evidence being excluded on a ground under s 135 of the Evidence Act. As such, the applicant contends that Mr Milledge’s opinion evidence ought not to have been excluded and that the matters arising from his cross-examination were applicable only to weight.

24    The applicant also contends (and the respondents accept) that the failure to draw the Court’s attention to the decision in Rush and subsequent authorities applying that decision cannot be attributed solely to the neglect or default of the applicant but is at least equally attributable to a failure of the respondents. Furthermore, while the applicant did not refer the Court to Rush, the applicant contends that its submissions accorded with Rush in that the applicant’s counsel submitted that being partial does not disqualify an expert.

25    The respondents, however, take issue with the applicant’s construction of the decision in Rush. They contend that it establishes only a general rule which leaves open the possibility that the Court may exclude evidence under s 79 of the Evidence Act in circumstances where an expert lacks independence and impartiality. So understood, the respondents submit that the Ruling did not proceed on a misapprehension as to the applicable law.

4.2.2    What did the decision in Rush hold?

26    The starting point is s 76(1) of the Evidence Act. Section 76(1) provides that “[e]vidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed” (the opinion rule). Section 79(1) creates an exception to the opinion rule, providing that:

If a person has specialised knowledge based on the person’s training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge.

27    Thus, as the High Court explained in Dasreef Pty Ltd v Hawchar (2011) 243 CLR 588 at [32] (French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ):

To be admissible under s 79(1) the evidence that is tendered must satisfy two criteria. The first is that the witness who gives the evidence “has specialised knowledge based on the person's training, study or experience”; the second is that the opinion expressed in evidence by the witness “is wholly or substantially based on that knowledge”.

28    The decision of Rush, on which both parties relied in support of their submissions, held at [32] that there is no third criterion requiring that an expert witness be independent and impartial, in addition to the two criteria in s 79(1) of the Evidence Act. So much was common ground between the parties. Rather, the issue between the parties is primarily whether Rush established that the actual or perceived lack of independence, impartiality or objectivity of an expert witness can go only to weight as opposed to admissibility under s 79(1), subject to exclusion on one of the discretionary grounds in s 135 of the Evidence Act.

29    The respondents in Rush objected to the tender of expert opinion evidence concerning the actor’s, Mr Rush’s, reputation on the ground that the experts were not independent because they both knew Mr Rush well and had a close relationship with him. The respondents did not however seek to cross-examine either expert in a voir dire as to their capacity to give impartial and objective opinions about matters within their area of specialised knowledge, notwithstanding their relationships with Mr Rush: Rush at [12] and [28]. The respondents’ objection in Rush relied “entirely” on rr 23.11 and 23.13(1)(h) in Part 23 of the FCR which provide that a party may call an expert only if the expert’s report complies with the Court’s Practice Note concerning expert evidence (GPN-EXPT): Rush at [13]. In turn, GPN-EXPT relevantly requires the expert to give independent and impartial evidence. It also provides that an expert witness is not an advocate for a party and has a paramount duty to assist the Court impartially on matters relevant to the witness’s area of expertise.

30    In holding that the expert opinion evidence of both experts should not be excluded on the grounds of a lack of independence or impartiality, Wigney J held that the admissibility of expert opinion evidence is governed by s 79 of the Evidence Act which imposes two preconditions (as I have earlier explained). However, his Honour held that “[n]othing in s 79 imposes an additional condition that the witness be independent or that his or her opinion is demonstrably objective or impartial” (at [32]). In his Honour’s view, the admissibility of expert opinion evidence is not governed by the FCR, GPN-EXPT, or the Code of Conduct (at [29]), and the relevant statement of duties and responsibilities of expert witnesses in GPN-EXPT and the Code of Conduct are admonitions to those giving expert evidence as opposed to exclusionary rules (at [34]). In a passage on which the applicant in this case placed particular emphasis, Wigney J held at [35]-[37] that:

35.    The relevant principle established by those and other authorities was neatly summarised by Dodds-Streeton J in Ananda Marga in the following terms (at [35]):

In my opinion, relevant authority establishes that while (as reflected by the Federal Court Practice Note and like curial protocols) objectivity and independence are sought of expert witnesses, such qualities are not preconditions of competence, even in the case of expert witnesses. The sanction for failure to fulfil the obligations imposed by relevant authority and curial protocols is not the exclusion of the expert’s evidence, but rather, the significant risk that it will fail to persuade.

36.    In other words, an actual or perceived lack of independence, impartiality or objectivity of an expert witness goes to weight, not admissibility.

37.    It follows that opinion evidence which otherwise complies with s 79 of the Evidence Act is not excluded because the expert is a party to the proceedings, or has a material interest in the proceedings, or is an employee of one of the parties: see Stamoulis at [211]-[219] and the cases there cited.

(Emphasis added.)

31    Wigney J also distinguished the case before him from Guy v Crown Melbourne Limited [2017] FCA 1104.

32    In Guy v Crown, Mortimer J (as her Honour then was) found that there had been “no attempt to comply with Part 23” of the FCR since the expert “has, candidly, disclosed that he is an advocate for the cause” of the party who proposed to call him (at [51] and [56]). Nor, Mortimer J considered, was there any reason to believe that the expert “would even consider attempting to proffer the declarations of independence required, or the acknowledgements of the need for independence” (at [56]). In those circumstances, Mortimer J refused to waive compliance with Part 23 of the FCR and admit the evidence, concluding at [58] that:

In those circumstances, it would be inimical to the structure and purpose of Part 23 to waive the requirements of that Part entirely; or of r 23.11. This Court’s Rules do not intend that there are two kinds of expert evidence admissible in proceedings in this Court – independent and non-independent; substantially compliant with Part 23 and wholly non-compliant. The purpose of Part 23 as a whole is to regulate the form and preconditions to admissibility of opinion evidence within the terms of s 79(1) of the Evidence Act. That is why substantial compliance (at least purported), or the capacity substantially to comply, with Part 23 must be, in this Court at least, a precondition to admissibility of evidence within s 79(1) of the Evidence Act.

33    Wigney J distinguished Guy v Crown first on the basis that, unlike the expert in Guy v Crown, “[t]here was and is … no demonstrated or demonstrable non-compliance with Part 23 of the Rules” on the part of either of the experts in Rush (at [25]). The fact that both experts had known Mr Rush for many years and were on close terms with him did not in and of itself establish that they could not give impartial and objective evidence concerning the matters referred to in their reports (at [27]). In addition, unlike the expert in Guy v Crown, both witnesses in Rush stated that they had read and understood GPN-EXPT and agreed to abide by it. Relatedly, his Honour held at [28] that there was no basis for disbelieving the experts’ statements, concluding that they were going to act as advocates for the party calling them, and/or finding that that the opinions they expressed in their reports lacked impartiality or objectivity.

34    Secondly, Wigney J held that the heavy reliance placed by the respondents on Guy v Crown was misplaced as Mortimer J did not say that the statement of principle by Dodds-Streeton J at [35] of Ananda Marga Pracaraka Samagha Ltd v Tomar (No 4) (2012) 202 FCR 564; [2012] FCA 385 was wrong. Rather, Mortimer J distinguished Ananda Marga on the basis that the expert in Ananda Marga had acknowledged the need for independence whereas in Guy v Crown there had been no compliance “at all” with Part 23 of the FCR (at [55]).

35    Finally, Wigney J held in Rush at [41] that:

Lest there be any doubt about it, however, to the extent that there is any inconsistency between Ananda Marga and Guy v Crown in relation to the matters of principle, I would follow Ananda Marga, which is entirely consistent with the long line of authority referred to earlier. The qualities of objectivity and independence on the part of an expert witness, as referred to in GPN-EXPT and the Code of Conduct, are not preconditions of competence. Rather, they are matters that may go to weight. That is not to say that Mortimer J was wrong to exclude the opinion evidence in the case before her Honour. The nature of the opinion evidence and the circumstances of the expert in Guy v Crown were exceptional. It is perhaps not difficult to imagine cases where the proposed expert is so fundamentally biased or conflicted that his or her opinion evidence should be excluded. But the exclusion in such cases would generally be either because the bias of the expert meant that the preconditions in s 79 were not met, or by operation of provisions such as s 135 of the Evidence Act, not by operation of the Rules, or GPN-EXPT or the Code of Conduct.

(Emphasis added.)

36    With respect to this passage, Lee J in McNickle v Huntsman Chemical Company Australia Pty Ltd (Expert Evidence) [2021] FCA 370 at [34]-[35] rejected the submission by Mr McNickle, relying upon Rush, that issues relating to a perceived lack of independence and impartiality cannot go to issues of admissibility, but rather only to weight. As Lee J held at [35]:

I think Mr McNickle puts the point too highly. A broad point was being made by his Honour in Rush, which is no doubt correct in the general run of cases. But I do not think this means there cannot ever be circumstances in which a lack of impartiality or objectivity would go to more than weight and would form a basis by which the proposed expert evidence would not be admitted. One would conceive of some circumstances where proposed expert evidence could fail to survive the balancing exercise required when applying s 135 of the Evidence Act, in that receiving such evidence would be of such limited assistance (by reason of its lack of independence, impartiality or objectivity) that it would be unfairly prejudicial to the other party or would result in an undue waste of time.

37    As Mr Korman for the applicant’s in this case submitted, Rush has been applied or cited with approval on many occasions including: Axent Holdings Pty Ltd t/a Axent Global v Compusign Australia Pty Ltd [2020] FCA 1373 at [809] (Kenny J) (holding that non-compliance with r 23.13 of the FCR, GPN-EXPT and the Code of Conduct went only to weight); Owners Corporation PS419696X v Goh (2021) 63 VR 497; [2021] VSC 126 at [74]-[77] (Garde J) (holding that, in light of Ananda Marga and Rush, the submission that an expert’s evidence should not be received because of his past membership of the Building Appeals Board, a decision of which was the subject of the judicial review application, could not be sustained); Pirmax Pty Ltd v Kingspan Insulation Pty Ltd [2022] FCA 1340 at [56] (Snaden J) (discussed below); Save our Strathbogie Forest Inc v Secretary to the Department of Energy, Environment and Climate Action [2024] FCA 317 at [354] (Horan J); Elanor Funds Management Ltd v Alceon Group Pty Ltd [2024] FCAFC 121 at [885]-[889] (O’Sullivan J).

4.2.3    Did the Ruling proceed on a misapprehension of the law?

38    As earlier explained, my attention was not drawn to Rush or other relevant authorities at the time I made the Ruling; nor was s 135 of the Evidence Act relied upon by the respondents at that time in support of their application to exclude Mr Milledge’s opinion evidence, although it is relied upon now in the alternative. Rather argument focused upon non-compliance with the independence and impartiality of experts required by the GPN-EXPT and Code of Conduct. I then excluded his opinion evidence for the reason that, although he was “very genuine [in his evidence] and he was prepared to accept where he had made mistakes”, he nonetheless “through his conduct … placed himself in a position where the court cannot be confident that he can bring the necessarily objective mind to bear on the issues that is required of an expert witness under the Code of Conduct”. However, as I have explained, that was not the correct test for excluding expert opinion evidence. Consequently, even though I do not agree with the applicant’s interpretation of what Rush decided, I accept that I proceeded at best on an incomplete or erroneous appreciation of the principles by which I should have approached the question of whether to exclude Mr Milledge’s opinion evidence.

39    Rather, the question of admissibility should have been approached by considering whether, by reason of Mr Milledge’s passionate advocacy against, and implacable opposition to, the Development:

(1)    I could not be satisfied that Mr Milledge’s opinion evidence was wholly or substantially based on his specialised knowledge, and that, as a result, the criteria in s 79(1) of the Evidence Act were not satisfied; or

(2)    if his opinion evidence were received, it would be of such limited assistance (by reason of its lack of independence, impartiality or objectivity) that it would be unfairly prejudicial to the respondents or would result in an undue waste of time under s 135 of the Evidence Act.

4.3    Should leave to re-open be granted?

40    With respect to the question of whether leave to re-open should be granted, the overarching test is whether it is in the interests of justice to grant leave.

41    In my view, it is in the interests of justice to grant leave to reopen the question of the admissibility of the expert opinion evidence of Mr Milledge for the following reasons.

42    First, for the reasons set out above, argument proceeded on an erroneous or incomplete appreciation of the relevant authorities and principles.

43    Secondly, the parties were agreed, and I accept, that in circumstances where there had been no oral evidence by experts with respect to the LNP and Koala, this was a case where the public interest in the finality of litigation carries less weight than in other circumstances.

44    Thirdly, as earlier mentioned, it is common ground that the failure to draw the Court’s attention to the relevant authorities cannot be attributed solely to neglect or default on the part of the applicant but is at least equally attributable to a failure on the part of the respondents.

45    Fourthly, I have given particular weight in the exercise of my discretion to the importance of Mr Milledge’s opinion evidence to the applicant’s case as he is the applicant’s principal expert on the LNP.

46    In this regard, Mr Korman for the applicant submitted that:

I can tell you that the particular prejudice we would suffer is that Mr Milledge is an acknowledged authority on potoroos. Associate Professor Wardell-Johnson has some knowledge of them; he is a generalist. But in our submission, the evidence that Mr Milledge has provided in his four reports is far higher quality and far more detailed, and is of particular assistance to the applicant. So that to lose the benefit of Mr Milledge’s evidence would be a substantial blow to the applicant because of his expertise, knowledge, no doubt on cross-examination, ability to answer questions more authoritatively.

But he is the expert, and there was at least one place I can recall where the associate professor says, “I defer to Mr Milledge on this issue,” or, “Mr Milledge identified as this and that, and told me that,” and so that, in terms of the potoroo, it would be a substantial blow for the applicant not to have the benefit of Mr Milledge’s evidence. … [I]t would be a substantial problem for the applicant not to have him.

47    Mr Korman also submitted that it would suffice for the applicant to succeed if it were able to establish that a referral should be made to the Minister with respect to only one of the five relevant threatened listed species, emphasising how critical a decision to exclude Mr Milledge’s opinion evidence could be to the applicants’ overall case.

48    In this regard, there is no evidence by any expert of any direct sightings of the LNPs on the Land and the question of whether there is any population of LNPs on the Land is in dispute. The opinion evidence of Mr Milledge and, to a lesser extent, the Associate Professor, as to whether, among other things, diggings on the Land are likely to have been made by the LNPs and as to the presence of alleged habitat for the LNP, is therefore of particular importance to the applicant’s case.

49    Thus, for example, with respect to the diggings:

(1)    Mr Milledge expressed opinions on whether his detections of diggings in 2011 and 2023 within the development site were likely to have been made by LNPs: see Mr Milledge’s first report dated 30 July 2024 at [21]-[25]; see also Mr Milledge’s third report dated 23 September 2024 at [20]. Mr Milledge conducted camera trapping surveys in Tyagarah Nature Reserve adjacent to the development site in conjunction with colleagues in 2015 and 2016, and also expressed the view based on those surveys that the population in that area “had declined and had probably been lost”: see Mr Milledge’s first report at [24]. In addition, Mr Milledge expressed opinions on whether diggings photographed and videoed by the applicant’s lay witnesses in 2023 and 2024 were made by LNPs: see Mr Milledge’s first report at [26]-[29]. However, the Associate Professor simply notes Mr Milledge’s assessments contained in Mr Milledge’s first report: see the Associate Professor’s second report dated 2 August 2024 at page 5.

(2)    Mr Milledge (in his fourth report dated 9 January 2025 at [23]) and the Associate Professor (in his third report dated 14 August 2024 at [144] and sixth report dated 14 February 2025 at [7]-[8]) respectively assess whether diggings they observed during a site visit on 7 August 2024 with David Newell were likely to have been made by LNPs.

(3)    In the Joint Expert Report on the LNP dated 24 September 2024, the Associate Professor states that the LNP “is confirmed to be present” on the development site, while Mr Milledge refers to his affidavit evidence as to the occurrence of the species on the development site.

50    The respondents, however, deny that there is any evidence of the presence of LNPs on the development site, relying upon the opinion evidence of their expert Mr Karl Robertson. As Mr Robertson concludes, “I do not believe sufficient evidence has been presented to make me confident there is a population of Long-nosed Potoroo within the Development Site or in the Lands to the south”: see the Joint Expert Report on the LNP at page 6. The question of whether there is any population of LNPs on the Land and whether there is a real risk of significant impact to this listed threatened species is therefore directly in issue between the LNP experts.

4.4    Should the opinion evidence of Mr Milledge be excluded?

4.4.1    The parties’ submissions

51    The applicant contends that, if leave to reopen is granted, Mr Milledge’s opinion evidence should not be excluded, because of Mr Milledge’s prior conduct, for the following reasons.

(1)    Relying upon Elanor, evidence of partiality by an expert should not result in the wholesale exclusion of their opinion evidence including that which is supported by rational arguments. Rather, those opinions should be evaluated on their merits having regard to the reasoning on which the opinions are based and whether any factual assumptions underpinning the opinions have otherwise been proved. Specifically, in Elanor at [404]-[405] O’Sullivan explained that:

[I]t is the facts and the reasoning and rationality of the opinions expressed which is the surest guide to the correct outcome. No doubt where an opinion on a particular matter rests on unexaminable matters of experience, then competing views might have to be resolved by reference to credibility or lack of independence. However, even then, it would generally be appropriate to take into account the relative experience of the competing experts in connection with the particular matter about which the opinion is expressed if there are rational reasons to infer that such experience is likely to translate into a more reliable opinion.

It is not generally appropriate to resolve a difference between experts by reference to a generalised cautionary approach based on lack of independence, as opposed to assessing the persuasiveness of the opinions in light of the facts and the reasoning upon which the opinion is based.

(Emphasis added).

(2)    The witness’s past advocacy “is one element that goes into the mix, and the court needs to look at the whole picture… [I]t’s the whole range of matters, such as demeanour, such as conduct in response to questions against interest, and the usual thing a court looks at to ascertain or to form a view as to the credibility of this witness”. As such, the Court ought not to prejudge the veracity of Mr Milledge’s opinions by excluding his opinion evidence altogether. In this regard, Courts are equipped to determine the extent to which his passionate advocacy may have influenced his ability to be impartial, having observed the witness’s demeanour and readiness to make concessions.

(3)    The respondents overstated the complexities of the Court assessing Mr Milledge’s opinion evidence. Rather in the applicant’s submission:

[W]here we have two experts with competing opinions, there will be cases where – and one would assume most cases – each expert has an argument and has reasoning. Neither of them might be the gold standard of satisfying every possible logical point, but they will both be arguments.

For example, in terms of the diggings, there’s a photograph of the digging, there’s guidelines which state what the diggings look like, there might be evidence from one expert saying it should be this shape, from the other expert saying it should be that shape, or they might agree on the shape. And then, faced with that evidence, the two experts will say why they have come to the conclusions they have. Now, your Honour is able to compare these arguments and to come to a conclusion as to which the court finds more compelling, more logically based, more reasonable. But there will be other cases where an expert says, “Look, this is what happens in practice”. And when asked why, the answer might just be, “I’ve been doing this for 20 years, and that’s what I’ve seen”. In that case, your Honour is not able to compare that with another expert who says, “Well, I’ve been doing it for 20 years, and I haven’t seen it”.

And those are cases where your Honour will have to weigh up everything. It doesn’t mean automatically that Mr Milledge would be the loser. It means that your Honour has to look at the situation, take account of all the various factors and come to a decision knowing that Mr Milledge has advocated in the past and knowing that he is at risk, one might say. But it doesn’t mean the court can’t evaluate the degree of that risk.

(4)    Mr Milledge acknowledged in each of his reports that he had read, understood and complied with GPN-EXPT and the Code of Conduct

(5)    Mr Milledge’s reports do not appear to contain views which cannot be sustained or reasoned. As Mr Korman submitted, “[N]o issue has been taken with anything in [his] reports which … might indicate an extreme degree of advocacy”.

(6)    In cross-examination as to his independence, Mr Milledge made a number of concessions against his interest, demonstrating an ability to remain objective. Thus, Mr Korman submitted that Mr Milledge “admitted … to matters that were very much against his interests, and he showed an ability, in this small amount of cross-examination, to take [a] step back and look at his own behaviour in an objective sense. So, again, I’m saying that the court cannot come to the conclusion at this stage, without having heard him [in concurrent sessions], that there is no utility in hearing his evidence”.

(7)    The reasons for the Ruling were expressed in tentative terms, including in particular that: (1) “it would appear, [he has] lost either the objectivity required of an expert witness under the code of conduct or gives the appear[ance] of having lost that objectivity. So how is it then that the court would be able to … feel confident that he was able to make appropriate concessions?”; (2) “through his conduct, he has placed himself in a position where the court cannot be confident that he can bring the necessarily objective mind to bear on the issues that is required of an expert witness under the Code of Conduct”; and (3) “I fear too that … the biases or the very strong views that he clearly holds may influence him”. Such tentative findings, Mr Korman submitted, reinforce the appropriateness of the Court admitting Mr Milledge’s opinion evidence and then taking his past conduct into account when determining the weight to be attributed to his opinion evidence.

(8)    Finally, Mr Korman submitted it is in the interests of justice that the Court exercise its discretion to set aside the Ruling for the following reasons:

On the one hand, this is not a case where “the public interest in the finality of litigation” will be undermined (see Romero at [11]). The proceeding is ongoing and there has been no joint expert session since the Ruling was made. The applicant merely seeks correction of an error of law as to admissibility before the relevant witness is due to give his testimony.

…

On the other hand, if the discretion is not exercised, the applicant will suffer a serious injustice. The Ruling has a significant effect on the applicant’s case, in particular in relation to one of the five subject species, the LNP. Mr Milledge, an undoubted expert on that species, and the applicant’s principal expert in relation to the LNP, would be prevented from giv[ing] opinion evidence on important factual questions relating to that species, including whether the various diggings on the site are attributable to the LNP, the importance of the population of the LNP on the site, and the significance of impacts on that population arising from the Development and Slashing Works.

52    On the other hand, the respondents submit, for the following reasons, that Mr Milledge’s opinion evidence is not admissible under s 79(1) of the Evidence Act because his opinion evidence is in the same exceptional category of expert evidence as that excluded in Guy v Crown.

(1)    Although it was not submitted that Mr Milledge was a “hired gun” for the applicant, there were “factually different ways in which independence or impartiality [of an expert] may be compromised” and that “all of those different ways may be reasons why” an expert’s opinion evidence is excluded.

(2)    It would not be possible for the respondents, or indeed this Court, to disentangle the “rational parts” of Mr Milledge’s opinion evidence from those affected by views which he has held “passionately and fervently” about the Development for some 15 years. In addition, Ms Davidson for the respondents submitted that “it will be difficult even for Mr Milledge himself … to compartmentalise, in his own mind, the views that he holds in respect of this development … with what are said to be rational parts of answers that he’s asked to give”, given his “lack of independence is so blatant” and given the extent of his advocacy against the Development.

(3)    Mr Milledge’s agreement to abide by the Code of Conduct should be given little weight as he did not candidly disclose in his reports any of the matters on which he was cross-examined on the voir dire. Thus, in the respondents’ submission, there “hasn’t been any conscious reflection in the preparation of his reports, on the extent to which his previous activities might have influenced his opinions”.

(4)    Given Mr Milledge’s evidence on the voir dire, the Court should find that Mr Milledge is not capable of the level of independence set out in the Code of Conduct and GPN-EXPT.

(5)    The fact that Mr Milledge’s reports are expressed in a scholarly and scientific manner does not assist the applicant in circumstances where the “lack of candour … contributes to the difficulty”. As explained, the Respondents submit that there has not been any “conscious reflection” by Mr Milledge on the extent to which his past behaviours may have influenced his opinions as expressed in the various reports. Mr Milledge’s evidence in cross-examination was that he considered “these proceeding … as another opportunity” to voice his opposition to the Development.

53    In the alternative, the respondents submitted that Mr Milledge’s opinion evidence should be excluded pursuant to s 135 of the Evidence Act, contending that they would be unfairly prejudiced if his opinion evidence were to be admitted.

4.4.2    The Ruling should be set aside

54    For the following reasons, I do not consider that Mr Milledge’s opinion evidence should be excluded by reason of his prior advocacy against the Development and passionate opposition either on the basis that the criteria in s 79(1) of the Evidence Act have not been met or in the exercise of discretion under s 135 of the Evidence Act.

55    First, the starting point is, as Dodds-Streeton J held in Ananda Marga at [52], that “[g]enerally speaking … lack of objectivity or deviation from the obligation of independence, whether exposed by cross-examination or other evidence, merely goes to impeach the credibility or reliability of the expert evidence in question”: see also e.g. Lee J in McNickle at [35].

56    Secondly, Mr Milledge is a wildlife ecologist whose standing is recognised within his field, having, among other things, authored or co-authored over 40 peer-reviewed scientific publications and having been included in a LNP working group convened in 2021 for the Commonwealth’s Regional Bushfire Recovery for Multiregional Species and Strategic Projects Program by the Victorian Department of Environment, Land, Water and Planning. As such, it can be anticipated that he understands the need for, and is capable of exercising, objectivity and impartiality in forming opinions on scientific matters within his field. Furthermore, on the face of the reports it appears that the opinions expressed by Mr Milledge are wholly or substantially based upon his specialised knowledge. However, I have given some, but only limited, weight at this stage to his readiness to make some appropriate concessions during cross-examination on the voir dire.

57    Thirdly, in each of his reports, Mr Milledge states that he has read, understood and complied with GPN-EXPT and the Code of Conduct. In contrast to the position in Guy v Crown, there is therefore at least purported compliance with GPN-EXPT and the Code of Conduct subject to Mr Milledge’s concession on the voir dire that he should have disclosed in his reports his prior advocacy against the Development, including at the request of the applicant. Mr Milledge’s failure to disclose his prior advocacy was a serious matter and indicates potential non-compliance with the GPN-EXPT and Code of Conduct. However, that does not necessarily mean that Mr Milledge may not otherwise have complied with GPN-EXPT and the Code of Conduct in reaching his opinions. Furthermore, his agreement with the respondents’ proposition that, when he prepared his expert reports for these proceedings, he “regarded that as another opportunity to put forward an explanation for why this development should not go ahead” (emphasis added) does not constitute agreement with a broader proposition (that was not put to him) that he regarded the expert reports as an opportunity to advocate against the Development. In this regard, Mr Milledge did not accept the proposition that he would pursue his opposition to the Development “by whatever means”. Indeed, as I said earlier, it was not suggested by the respondents that he was a “hired gun” for the applicant.

58    Fourthly, as the applicant contends, I consider that the respondents’ submissions, with respect, overstate the difficulties they may encounter in cross-examination if Mr Milledge’s opinion evidence is admitted. Subject to considering any objections by the respondents, Mr Milledge’s reports largely appear to set out the bases for his opinions. Where this is (arguably) not the case, the respondents will, no doubt, seek to have that evidence excluded or submit that weight cannot be given to those views.

59    Moreover, the differences between Mr Milledge’s views and those of the respondents’ experts have been exposed through reports in response to each other’s expert reports and in the joint expert reports. Furthermore, the respondents’ experts will have a further opportunity to directly respond to, and challenge, Mr Milledge’s opinions, topic by topic, while giving evidence in concurrent sessions. As mentioned, the respondents will, no doubt, also make submissions in due course as to the weight, or lack thereof, which can be given to Mr Milledge’s opinion evidence in light of his prior advocacy where there is disagreement between him and their own experts, and no independent evidence to support, or apparently rational bases for, all or some of Mr Milledge’s opinions. As the applicant contends, other factors will likely play a part in the Court’s assessment of Mr Milledge’s credibility, including his willingness to make appropriate concessions in the giving of his evidence in concurrent sessions. It must further be borne in mind that his passionate views against the Development do not rule out the possibility that his views are based on rational grounds insofar as they relate to areas within his expertise.

60    In these circumstances, I do not accept the respondents’ contention that Mr Milledge’s opinion evidence cannot be properly tested by them by reason of his prior involvement in advocating against the Development and his passionate views. By contrast in Pan Pharmaceuticals Limited (In Liquidation) v Selim [2008] FCA 416, for example, the long prior involvement of the expert witness with the liquidators and their solicitors in relation to the proceedings, coupled with the insistence on professional privilege by the liquidators, led Emmett J to hold at [157] that the expert’s evidence “cannot be properly tested. It should be afforded so little weight that its exclusion would not prejudice the Liquidators’ case”.

61    In the fifth place, the matters identified above highlight points of difference from the circumstances considered in Guy v Crown. In that case, Mortimer J held that “there must be substantial, at least purportedly substantial, compliance with Part 23, or a capacity substantially to comply with Part 23” of the FCR (at [50]).

62    Mortimer J held that the applicant’s expert in poker-machine gambling, Dr Livingston, had no capacity to comply because (1) he had disclosed that he was an advocate for the cause of the applicant (at [51]), (2) he had been assisting the applicant and her legal representatives (at [51]), and (3) he had also acquired the Dolphin Treasure machine which Mortimer J described as “an important foundation for the applicant’s ACL allegations” (at [23]). Mortimer J also held that Dr Livingston made no attempt to comply with Part 23 of the FCR (at [51]), and that there was “no reason to believe Dr Livingstone would even consider attempting to proffer the declarations of independence required, or the acknowledgments of the need for independence” (at [56]). In effect, her Honour held that waiver of all of Part 23 of the FCR would be required for Dr Livingstone’s opinion evidence to be received (at [13]).

63    In the sixth place, I respectfully agree with Wigney J in Rush at [41], that, to the extent that there is inconsistency between Ananda Marga and Guy v Crown in relation to matters of principle, the decision in Ananda Marga should be followed because it is “entirely consistent with the long line of authority” discussed by Wigney J in Rush.

64    As explained, Rush held that there is no third criterion, in addition to the criteria in s 79(1) of the Evidence Act, which requires that an expert witness be independent and that their opinion is demonstrably objective or impartial. Consequently, determining whether Mr Milledge’s opinion evidence is admissible requires answering: (1) whether his opinion evidence fails to satisfy the two criteria in s 79(1) of the Evidence Act and should therefore be excluded; and (2) whether his opinion evidence should otherwise be excluded in the exercise of the discretion under s 135 of the Evidence Act.

65    The Respondents did not contend that Mr Milledge’s opinion evidence should be excluded in whole because it failed to meet the criteria in s 79(1) of the Evidence Act other than by reason of it being in an “exceptional” category akin to the opinion evidence in Guy v Crown. However, while Mr Milledge’s prior advocacy renders this an unusual and troubling case, I do not accept (at least at this stage) that this is an exceptional case in the same category as Guy v Crown. This is because I do not accept that the evidence presently establishes that Mr Milledge is “so fundamentally biased or conflicted” that I cannot be satisfied that his opinion evidence was based wholly or substantially upon his specialised knowledge. As a result, in my opinion, the real question is whether Mr Milledge’s opinion evidence should be excluded under s 135 of the Evidence Act on the ground that it would unfairly prejudice the respondents to admit his opinion evidence.

66    In this regard, Snaden J in Pirmax held at [60] that:

As to s 135 of the Evidence Act, Dr Barnett’s evidence plainly holds at least some probative value (even if the resolution of this matter does not turn solely upon it). The question then, is whether that value is substantially outweighed by any unfair prejudice that the receipt of that evidence would visit upon Pirmax. It is not. The prejudice to Pirmax, though obvious, is not unfair: Dr Barnett was not a partial expert, nor one whose independence from Kingspan was improperly or impermissibly compromised. But, even if he was, his evidence remained of some significance. I do not consider that any unfair prejudice attending its receipt substantially outweighs that probative value.

(Emphasis added).

67    Equally in this case, I do not consider that any prejudice flowing from the receipt of Mr Milledge’s opinion evidence for the respondents substantially outweighs the probative value of that evidence. For the reasons I have earlier explained, I respectfully consider that the respondents have overstated the difficulties which receipt of Mr Milledge’s opinion evidence may pose for them in terms of being able to test and respond to that evidence. Furthermore, as earlier explained, Mr Milledge’s opinion evidence remains potentially of significance to the applicant’s case overall which is a factor to which I have attached particular weight.

5    CONCLUSION

68    For these reasons, I consider that leave to re-open the Ruling should be granted and that the Ruling should be set aside. This does not, however, mean that the whole of Mr Milledge’s opinion evidence will necessarily be received in evidence. This is because the respondents foreshadowed a need to resolve other objections to Mr Milledge’s opinion evidence in the event that the Ruling was set aside. I will reserve the question of costs.

Associate:

Dated: 22 April 2025