Home >  Blog >  Expert's Report - Beware of Assumptions

Expert's Report - Beware of Assumptions

Posted on 11 May 2021

Source:  Ian Neil, McCarthy Durie Lawyers

Although the issues concerned an Accountant's expert report in Queensland Supreme Court civil litigation1, the Court's consideration of the issues are no doubt relevant to experts' reports in the Planning & Environment Court and Land Court jurisdictions. Indeed, it is probably fair to say that many expert reports in those jurisdictions, possibly for reasons of complacency in instructions provided or the expert's frequent engagement in the jurisdictions, contain assumptions about the subject matter or the reader's interpretation of the expert's reasoning.

In Springfield City Group v. PIPE Networks, the Plaintiff sought to prove the quantum of its claim for damages and account of profits by way of an accountant's expert report. The accountant had appropriate professional qualifications and experience.
The expert's initial report was ruled by the Court to be inadmissible because the report proceeded by reference to a particular set of assumptions (as to the operational and financial performance of the subject matter of the dispute). The Court allowed the expert's report to be resubmitted. However, the subsequent report also "relied on assumptions not sufficiently identifiedand relied on reasoning which was not sufficiently exposed".

The Defendant sought to have the further report ruled inadmissible in the proceedings. However, Bond J held that "the relevant rule of admissibility is not that the expert's reasoning be perfectly articulated", nor that the "expressed reasoning be of such detail or cogency that, without more, the Court would inevitably accept the opinion as sound and give it full weight". Instead, what was required was only that "the expert must state, in chief, the reasoning by which the conclusions arrived at flow from the facts proved or assumed by the expert so as to reveal that the opinions expressed are based on the expert's expertise". His Honour quoted Dixon J with approval, who had observed in Wilson v Bauer Media (No 7) [2017] VSC 357
that: "It is not the court's function when the question of admissibility arises to engage in a comprehensive assessment of the reasoning. That is a matter best explored either in cross-examination or in submissions."

Although Bond J ultimately concluded that the relevant report satisfied the test for admissibility, quite obviously the parties had been put to substantial costs and the Court's time wasted in arguing such matters. And the Plaintiff's case (and the expert's credibility) was quite obviously weakened by the flaws in the expert's report.

It is incumbent on instructing solicitors to give clear instructions to experts, for experts to clearly state the basis of the expert's conclusions, and for instructing solicitors and Counsel to stridently review any preliminary conclusions of experts engaged. The last step is always best done by means of a draft report, not for the purposes of coaxing an expert to a desired conclusion but for the purposes of ensuring that the information to be provided to the Court is soundly based.