Full Federal Court provides clarity on expert evidence preparation

Articles Written by Christine Small (Partner), Alice Colquhoun (Associate)
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On 10 May 2023, in the unanimous five-judge decision of New Aim Pty Ltd v Leung [2023] FCAFC 67, the Full Federal Court provided some long awaited guidance on the preparation of expert reports and the appropriate involvement of lawyers.

The key takeaways for lawyers involved in preparing expert evidence include: 

  1. There is nothing unusual in finalising the questions to be answered by an expert shortly before an expert report is finalised, particularly where the issues are novel or complex.
  2. Lawyers are under no legal obligation to disclose their involvement in, or correspondence relating to, the preparation of an expert report.  Whether there is an ethical obligation to do so depends on the particular circumstances.
  3. One of the core ethical requirements on legal practitioners involved in the preparation of expert evidence is a requirement not to influence a witness’ evidence, whether a witness of fact or an expert witness.

Decision at first instance

New Aim Pty Ltd (New Aim)’s claims were dismissed at first instance for several reasons, including because the evidence of New Aim’s expert witness, Ms Chen, was rejected.

In dismissing Ms Chen’s expert report, the trial judge held that the law firm’s involvement in its preparation “went far beyond the permissible scope of involvement of lawyers who retain an independent expert in order to give evidence in a proceeding”. His Honour noted that:

  • the timing of the expert report, being a 16 page forensic report, was dated only one day after the witness had been provided with a letter of instruction; and
  • the contents of the report itself, bore a “striking similarity” to another of New Aim’s lay witness statements.

His Honour stated that this left him in “a state of uncertainty as to who was responsible for drafting [the] report”, which led him to conclude that “the report was, at least initially, the product of drafting by the lawyers”.

Decision on appeal

New Aim appealed the decision on a number of grounds, including that the primary judge had erred in rejecting Ms Chen’s expert evidence.

The Full Federal Court upheld New Aim’s appeal and ordered that its claims be remitted for re-trial.

In arriving at this conclusion, the Full Court considered each of the key issues raised by the primary judge, such as the timing of the written expert report and the suspected involvement of New Aim’s lawyers. In doing so, the Full Court provided some useful clarification on the expectations on solicitors in relation to the preparation of expert reports.

Timing of the report

Despite agreeing that the process of instructing an expert should be clear and transparent, the Full Court disagreed with the primary judge’s view that the one day difference between the letter of instruction and the expert report was “misleading”.

Rather, in observing the “common practice” of refining the formulation of questions asked of the expert prior to issuing a letter of instruction in final form, the Full Court cited the decision of BrisConnections Finance Pty Ltd (Receivers and Managers Appointed) v Arup Pty Ltd [2017] FCA 1268 and noted that (emphasis added): 

[…] it is not unusual in a number of contexts not to finalise the formulation of the question asked of the expert without first discussing the issues with the expert. It would be expected, for example, that a solicitor would engage with an expert in a specialised field of scientific knowledge about how to frame a question so as not to give rise to a nonsensical question or one which misses the real issues or one which fails to engage with all of the issues. This is not an inversion of a process which must be necessarily followed of first asking a question and then having its inadequacies pointed out. The laborious following of such a process is likely to result in increased costs and delay for the parties and ultimately a waste of the Court’s time.         

Their Honours held that the present case, unlike BrisConnections, was not one in which the “true instruction” to the expert was oral, and only emerged in the evidence during the trial. Rather, the letter of instruction, despite being reduced to writing only the day before the expert report was filed, was sufficiently transparent, in the sense that it clearly outlined the question that the expert was required to address.

Involvement of New Aim’s solicitors   

As to the involvement of New Aim’s solicitors, the Full Court found that the statement that “most of the report was, at least initially, the product of drafting by the lawyers”, ignored the fact that most of the expert report was factual in nature, as opposed to expert opinion evidence.

Despite acknowledging the perceived bias that might arise where a legal practitioner assists in drafting expert evidence, the Full Court rejected the idea that this type of involvement will be inappropriate in all cases, noting that there are “a number of situations´ in which this might be appropriate or even necessary, such as where there are “physical, language or resource difficulties”.

Further, the Full Court observed that it would be “difficult to conceive” a situation in which a solicitor, acting appropriately and ethically, would deliberately impose their own views into a report.  

The primary judge at first instance held that legal practitioners involved in preparing an expert report must disclose:

  • all written communications between the practitioners and the expert with respect to the preparation of the report;
  • any oral advice conveyed to the expert; and
  • if legal practitioners are involved in drafting the report, the fact of this involvement.

The Full Court considered that, whilst the disclosure of these things might be “desirable” or forensically advantageous in some cases, there is no legal obligation on practitioners to do so, and whether there is an ethical obligation to do so will depend on the circumstances.


This decision of the Full Court provides useful guidance on the preparation of expert evidence for use in court proceedings, and ultimately reflects a less restrictive approach than the decision at first instance, recognising that the appropriate involvement of lawyers may vary according to the particular circumstances. 

Important Disclaimer: The material contained in this article is comment of a general nature only and is not and nor is it intended to be advice on any specific professional matter. In that the effectiveness or accuracy of any professional advice depends upon the particular circumstances of each case, neither the firm nor any individual author accepts any responsibility whatsoever for any acts or omissions resulting from reliance upon the content of any articles. Before acting on the basis of any material contained in this publication, we recommend that you consult your professional adviser. Liability limited by a scheme approved under Professional Standards Legislation (Australia-wide except in Tasmania).

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