Parties and Advocates as Expert Witnesses in TASCAT

Occasionally parties or advocates in planning appeals will also seek to give expert evidence. Their interest in the outcome of the appeal is a matter for weight rather than admissibility.

Most parties appearing in the Planning Stream of TASCAT are represented, but self represented parties are not uncommon. Occasionally a self-represented party or lay advocate will also seek to give expert opinion evidence where that person has expertise in a relevant discipline, such as architecture, planning or engineering.

There is an inherent friction between the roles of expert and advocate. This is reflected in the Expert Witness Code of Conduct in the Practice Directions, which describes an expert’s overriding duty to assist the Tribunal impartially on matters relevant to the expert’s area of expertise and observes that an expert witness is not an advocate for a party.

Experts who also appear as advocates risk blurring the roles. A common example is where they attempt to include submissions in evidence or evidence in submissions. It is common for experts to describe their understanding of provisions in a planning instruments in formulating opinions addressing those provisions, but it is not the role of an expert to tell the Tribunal how the law should be interpreted or applied to facts. That is the role of an advocate.

There is competing English authority as to the admissibility of evidence by an expert who might not be independent. In Liverpool Roman Catholic Archdiocese Incorporated v Goldburg (No.2) [2001] 4 All ER 950 Evans-Lombe J refused to admit the evidence of a barrister called as an expert in a complex tax matter because he was a long standing friend of the defendant (also a barrister). His Honour applied a test similar to that of apprehended bias, saying “where it is demonstrated that there exists a relationship between the proposed expert and the party calling him, which a reasonable observer might think was capable of effecting the views of the expert, so as to make them unduly favourable to that party, his evidence should not be admitted however unbiased the conclusions of the expert might probably be”.

In Factortame Limited & Ors v Secretary of State for the Environment Transport and the Regions (No.2) [2002] 4 All ER 97 the Court of Appeal formed a different view, in respect to evidence of an expert who was employed by one of the parties, that disinterest is not automatically a precondition to the admissibility of evidence, but still contemplated that an expert who has an interest in the outcome of the case might not be permitted to give evidence.

Liverpool Roman Catholic Archdiocese Trust v Goldburg was considered by Pagone J in the Supreme Court of Victoria in Fagenblat v Feingold Partners Pty Ltd [2001] VSC 454. His Honour considered an objection to the admission of evidence of an accountant who was a member of a firm who had been the longstanding accountants of the defendant law firm, and who was also the brother-in-law of the plaintiff who was a former member of that law firm. He observed that an expert witness “has a special and important role…to assist the court by providing objective and unbiased opinions about matters that bear upon the determination which the court is called upon to make”. However, his Honour concluded that a biased witness does not impugn the independence of the court, particularly in adversarial proceedings where evidence can be tested. He considered that expert evidence should only be excluded where the court is satisfied that it is unsound and cannot provide probative material of value to determination of the issues. His Honour treated the actual or perceived bias of an expert witness as a matter for weight not admissibility.

That decision was overturned on appeal in FGT Custodians Pty Ltd (formerly Feingold Partners Pty Ltd) v Fagenblat [2003] VSCA 33, however the Court of Appeal determined that Pagone J was correct in his approach to admissibility of the evidence. Ormiston J.A. noted that it will also apply where the witness is a party. His Honour concluded a lengthy consideration of the authorities with the observation that “[h]owever desirable it may be, as a matter of common sense in the presentation of a party’s case, that an expert witness be seen to be independent, there is therefore no authority requiring this Court to hold that an “interested” expert’s evidence be rejected because of a “perception” that the witness might favour the party seeking to adduce that evidence”.

The weight given to opinion evidence by a witness who also an advocate will depend, like any expert, on the nature and extent of the witness’s expertise, the factual basis on which the opinion is expressed and the disclosed reasoning process behind the opinion, but it may also be influenced by interest. Parties who give opinion evidence would be wise to note the comment by Kefford ECJ in the Planning and Environment Court of Queensland in DVB Projects Pty Ltd v Council of the City of Gold Coast [2022] QPEC 40 that “an expert who adopts an advocate’s approach risks presenting evidence that is regarded by the court as unhelpful or self-defeating in the sense of the evidence not being reliable”.

Richard Grueber
Deputy President and Division Head (General)
TASCAT