The Supreme Court of Canada issued a decision today which furthers existing law requiring experts in court proceedings to give fair, objective and non-partisan opinion evidence. A number of cases stood for the proposition that, if there was some doubt about the objectivity of the expert, that was a matter that would go to “weight”, but the evidence would still be admissible. Not so, declared the Supreme Court today. In White Burgess Langille Inman v Abbott and Haliburton Co, the Supreme Court held that the expert’s duty to the court creates a threshold requirement for the admissibility of the expert’s evidence.

The decision arose out of a professional negligence action in which the plaintiffs, a group of shareholders, sued their former auditors. The shareholders had retained a new accounting firm (Grant Thornton of Kentville, Nova Scotia), who discovered problems with the former auditors’ work. Specifically, the shareholders alleged that they suffered a financial loss because of the former auditors’ failure to apply generally accepted auditing and accounting standards.

In August 2010, the auditors moved for summary judgment. In response, the shareholders retained an expert witness to review the materials and prepare a report. The expert witness worked at Grant Thornton’s Halifax office (100 km from Kentville). The former auditors applied to have the expert’s affidavit struck because her firm could be exposed to liability if its approach was not accepted by the court and that the expert, in turn, could be personally liable. The shareholders argued that the expert had a personal financial interest in the outcome of the litigation and was not an impartial witness.

The Nova Scotia Supreme Court agreed with the shareholders finding that, to be admissible, an expert’s evidence must be, and be seen to be, independent and impartial. In a split decision, the Nova Scotia Court of Appeal concluded that the independent and impartial test applied by the lower court was wrong in law. The appeal was dismissed and that decision was appealed to the Supreme Court of Canada.

Justice Cromwell, who delivered the judgment of the Court, affirmed that expert witnesses have a special duty to the court to provide fair, objective and non-partisan assistance. The question was where this duty fit into the legal framework for expert opinion evidence as established by the seminal Supreme Court case of R v Mohan. The Mohan framework has two main components:

  1. First, four threshold requirements must be met for the evidence to be admissible:
  1. relevance;
  2. necessity in assisting the trier of fact;
  3. absence of an exclusionary rule; and
  4. a properly qualified expert.
  1. If the requirements under the first component are met, the judge holds a residual discretion to exclude evidence based on a cost-benefit analysis.

Justice Cromwell held that the expert’s duty to the court fit under the “properly qualified expert” requirement under the first component of the Mohan framework. Less fundamental concerns about an expert’s independence and impartiality should be considered under the cost-benefit analysis in the second component of the Mohan framework.

The most important part of the decision, in practice, may relate to new rules established by the Supreme Court relating to onus of proof. First, the expert is required to testify or attest (in a report or otherwise) that he or she is willing and able to provide unbiased, independent and impartial evidence. Then, the burden is on the other party to show that there is a realistic concern that the expert’s evidence should not be received because the expert is unable or unwilling to comply with his or her duties. If that threshold has been met, the onus then shifts back to the party seeking to adduce the expert evidence to prove on a balance of probabilities that the expert is sufficiently independent and impartial so as to make the evidence admissible.

In addressing the application of that threshold, Justice Cromwell explained that it would be rare that a proposed expert’s evidence would be ruled inadmissible for failing to meet it. In determining whether the expert can meet the threshold, the court must consider the nature and extent of the interest or connection with the litigation or a litigant. The acid test is “whether the expert’s opinion would not change regardless of which party retained him or her”.

Applying the above principles to the facts, Justice Cromwell concluded that the expert’s evidence was admissible. There was no finding that the expert was biased or partial or that she was acting as an advocate for the shareholders. That the expert worked out of a different office of Grant Thornton did not render the evidence inadmissible. Justice Cromwell further refused to accept that relying on the work of other professionals in reaching an opinion rendered an expert’s report inadmissible. This is an important aspect of the decision for accounting or financial experts, who often rely on the work of others in formulating the opinion.

White Burgess reaffirms the importance of experts knowing their duty to the court. That duty trumps all other duties. This is now elevated to an admissibility issue, meaning that, if the expert cannot satisfy the Court that he or she is able and willing to provide impartial and unbiased opinion evidence, that evidence will never find its way into a courtroom.