The Federal Court of Australia in New Aim Pty Ltd v Leung [2022] FCA 722, following the cross-examination of the plaintiff’s only expert, rejected the entirety of the expert’s evidence, including the expert’s report and oral evidence. Consequently, the plaintiff was unable to prove a central issue in the dispute, and the plaintiff’s case failed. Along the way to rejecting the plaintiff’s claim, McElwaine J made a number of adverse findings in relation to the overinvolvement of the plaintiff’s solicitors in the preparation of the expert’s report, as well as a finding that the conduct engaged in preparing and delivering the expert’s report, and the expert’s report itself, was misleading.

The decision serves as a reminder that:

  • an expert witness’s paramount duty, overriding any duty to the party retaining the expert, is to assist the court impartially on matters relevant to the expertise of the witness;
  • it is not the role of an expert witness to act as an advocate for the party retaining the expert;
  • expert evidence presented to the court should be, and should be seen to be, the independent product of the expert, uninfluenced by the pressures of litigation;
  • counsel and solicitors have a proper role to perform in the preparation of expert evidence, including ensuring the report is directed to the issues before the court and that the form of the report addresses the legal tests of admissibility for expert evidence; pointing out any obvious inconsistencies or gaps in reasoning; and ensuring the report accurately states the propositions the expert would advance;
  • however, it is not permissible for counsel or solicitors to attempt to invite the expert to misstate facts or proffer opinions not honestly held by the expert, or otherwise influence the report in any way which may cause the report to lose its essential character as an independent report; and
  • care should be taken to avoid communications which may undermine, or appear to undermine, the independence of the expert, and to ensure that the conduct engaged in preparing and delivering the expert’s report, and the expert’s report itself, is not in any way misleading.

Background facts

The plaintiff, New Aim, conducted a large-scale e-commerce business in Australia, sourcing products from a range of suppliers in China. New Aim commenced proceedings in the Federal Court in 2021 against three of its former employees and two of its competitors, claiming declaratory and injunctive relief, damages, delivery up and an account of profits in relation to allegations of misuse of New Aim’s confidential information, being the identity and contact details of certain suppliers of New Aim.

The plaintiff’s solicitors engaged a businesswoman with relevant industry experience and knowledge and instructed her, by way of letter, to prepare an expert report on business practices in the e-commerce sector concerning the use and treatment of information pertaining to the identities and details of suppliers in China.

The plaintiff’s expert delivered her 16-page expert report within only one day of receiving her letter of instructions. That fact became the subject of detailed cross-examination at trial by counsel for the respondents, and the expert’s answers caused the judge, McElwaine J, who admitted the report into evidence after ruling on various objections to it, to conclude that he should reject each of the statements of fact and opinions contained in the report, as well as the expert’s oral evidence.

During cross-examination, the plaintiff’s expert initially said she had prepared the report “within 24 hours”, but then disclosed that she had “a couple of conversations” with the plaintiff’s solicitors in the months prior to her letter of instructions, and accepted that she had sent drafts of her report to the plaintiff’s solicitors for comment, and that she had received comments from the plaintiff’s solicitors during a video conference. She denied receiving comments in writing, by email or otherwise, and when pressed as to whether the solicitors suggested to her that she should make changes to her draft report, she gave inconsistent answers and was at times unresponsive. Eventually, she was asked who drafted the version of the report attached to her witness statement. She answered that she had “started first”, but then admitted that one of the plaintiff’s solicitors had “put together” the second draft.

The respondent’s counsel then questioned the expert as to who was responsible for the drafting of which portions of her report, drawing her attention to certain paragraphs of her report which were similar to paragraphs in another witness’s statement. Eventually, the expert conceded that she had received emails from the plaintiff’s solicitors, the effect of which was to suggest that she make changes to her draft report. This prompted the respondents’ counsel to call for production of those emails. Emails from the plaintiff’s solicitors were produced which included statements such as “we are progressing your witness statement and would like to arrange a call with you next week to discuss it further”, and “we are in the process of finalising your statement and hope to have it to you soon”. The versions of the draft witness statement and expert report attached to the emails from the plaintiff’s solicitors were not materially different from the final expert report.

In light of what was revealed in those emails, the expert accepted, in further cross-examination, that her report was a collaboration between her and the plaintiff’s solicitors, and that certain paragraphs appearing at the end of her report, which stated various opinions, had been drafted by the plaintiff’s solicitors but “reflected her opinion”. Given the abovementioned similarity between certain sentences in those paragraphs and the paragraphs in another witness’s statement, McElwaine J inferred that those sentences were drafted by the same lawyer or lawyers from the plaintiff’s solicitors.

Rejection of the expert’s evidence

Justice McElwaine said he was left in a state of uncertainty as to who was responsible for the drafting of which portions of the expert’s report, and that it appeared that most of the report was the product of drafting by the lawyers, relying only on some non-specific material which the expert had provided.

Further, McElwaine J considered that the conduct engaged in preparing and delivering the expert’s report, and the expert’s report itself, were misleading. The conduct was held to be misleading because the letter of instruction conveyed the representation that the expert was engaged prospectively to consider and prepare a report answering the questions the subject of her instructions, whereas draft versions of her report had been prepared by the plaintiff’s solicitors in the weeks prior. The report itself was held to be misleading because, in his Honour’s view, the involvement of the plaintiff’s solicitors in the preparation of the report ought to have been disclosed in the report, together with a copy of all correspondence relating to the manner of preparation of the report. His Honour observed that “in this case, that fact was not only withheld but was only ascertained during the course of cross-examination…which in my opinion, was grossly unsatisfactory”.

Ultimately, McElwaine J said that he could “not be satisfied that the opinions expressed in the report…truly represent her honest and independent opinions and that no matters of significance have been withheld”. His Honour therefore rejected the report in its entirety and, lacking confidence that the witness’s “oral evidence was untainted”, refused to make any finding based on her evidence.


The court’s rejection of the expert’s evidence ultimately led to the plaintiff’s case failing. New Aim had intended to place substantial reliance on the expert’s evidence in support of its proposition that the confidential information at the heart of its claim had particular commercial value to the respondents. As it was unable to rely on the expert’s evidence, it was left to rely on limited lay evidence which, the court found, was insufficient to support that proposition. Accordingly, the claim was dismissed.

Expertise Area