Busting ghostwriters – expert witnesses beware!

Opinion evidence is not ordinarily admissible evidence before a court, but expert evidence is a particular exception, because it provides a court with information which is likely to be outside the experience of a judge or jury but is within the specialised knowledge of the expert. But although the expert is called by one side, that doesn’t mean the expert can be an advocate for that party.

In New Aim Pty Ltd v Leung [2022] FCA 722, a failure to maintain the proper independence expected of an expert witness had catastrophic consequences for one party’s case, but provided greater clarity about the scenarios that might offend this principle.

The non-independent expert witness

In New Aim Pty the applicant engaged an expert witness to produce a report on the use and treatment of information relating to the identities and details of suppliers in China. The expert was engaged based on her relevant industry experience and knowledge.

After hearing the cross-examination of the applicant’s expert, Justice McElwaine rejected all of her evidence, including her report and oral evidence. The result was devastating to the applicant as the lack of proof on this key issue was crucial to its case. This was in large part the result of the following sequence of events:

1. a letter of instruction from the applicant’s lawyers to the expert was dated only one day prior to the date of the expert’s report, but it conveyed the representation that the expert was engaged to prospectively consider a series of questions the subject of instruction;
2. the expert was asked in cross-examination whether she had drafted the entire report by herself within a space of 24 hours – she answered in the affirmative;
3. the expert later admitted that she had spoken to the applicant’s lawyers prior to the date of the letter of instruction and had produced “about two or three” draft reports which were the subject of their comment and drafting;
4. it eventually emerged that the expert was unable to identify which portions of her expert report were drafted by her and which portions were drafted by the lawyers, though she accepted that certain conclusory statements were drafted by the lawyers (statements which were very similar to the witness statement of one of the applicant’s other witnesses);
5. the expert also accepted that this drafting had selectively reproduced portions of a book she had written on the topic which were favourable to the applicant’s case.

   Accordingly, Justice McElwaine held that the expert’s impartiality was substantially undermined by her failure to disclose how her expert report was prepared. He also found that that the solicitors’ conduct in preparing and delivering the expert’s report was itself misleading because it gave the impression that they weren’t substantively involved in preparing the report before that point.

   Consequently, he was not satisfied that the opinions expressed in the report represented the expert’s honest and independent opinions, nor that she had not withheld any matters of significance.

   Additionally, Justice McElwaine had no confidence that the expert’s oral evidence was untainted by the factual material and the opinions expressed in her written report, as well as the manner of its preparation. As a result, he declined to make any factual findings based on any of her evidence.

   This case shows that where it is unclear who is responsible for the drafting of any given portion of an expert report, there is a risk that all of the evidence in such a report may be held inadmissible as a consequence.

   Involvement of lawyers with report drafting

   The court noted that, in some circumstances, the fact that an expert witness may agree with a form of words for the expression of the expert’s opinion, which are put to the expert in an admissible form, may not detract from the independence of the expert and the reliability of their opinion expressed. Indeed, Justice McElwaine observed that lawyers should be involved in the writing of reports by experts on matters of form. His Honour confirmed that it may be perfectly appropriate, such as in cases where an expert is unfamiliar with the form and content requirements for an expert opinion report, for that document to be settled in an admissible form by someone else provided that that fact is disclosed in the report.

   There may even be circumstances where it is proper for lawyers to draft an independent expert witness statement under the directions of, or for consideration by, an expert, but that fact must be disclosed in the report.

   The guiding principle is that care should be taken to avoid any communication which may undermine, or appear to undermine, the independence of an expert.

   Letters of instruction

   Justice McElwaine noted that letters of instruction to an expert should not convey the representation that an expert will, upon receipt of instructions, set about preparing a report, if that is not in fact the case.

   The fact that the author of a letter of instructions asks questions for which they already know the content and form of an expert’s answers is relevant in this respect.