On April 30, 2015, the Supreme Court of Canada (SCC) released its decision in White Burgess Langille Inman v. Abbott and Haliburton Co. (White Burgess), relating to courts’ assessment of the impartiality and independence of expert witnesses. In a unanimous decision, the SCC held that the impartiality and independence of expert witnesses is a factor to be considered when determining whether expert evidence is admissible. The SCC went on to articulate a threshold for admissibility and a framework for performing the admissibility analysis.

In White Burgess, shareholders launched a professional negligence action against the corporation’s former auditors. The auditors sought summary judgment. The shareholders adduced expert evidence on the summary judgment motion from the corporation’s current auditors, albeit from a partner in a different office than the office serving the corporation. The former auditors challenged the admissibility of the expert evidence on the grounds that it was not impartial and independent.

The motion judge ruled that the plaintiffs’ expert evidence was inadmissible because it did not appear to be impartial. The Nova Scotia Court of Appeal overturned the trial decision, holding that the motion judge applied the wrong test. The SCC agreed with the Court of Appeal’s ruling and dismissed the appeal, holding that the expert evidence was admissible.


Recognizing that an expert has an overriding duty to the court to give fair, objective and non-partisan opinion evidence, the SCC first considered whether the independence and impartiality of an expert witness bears on the admissibility of that expert’s evidence, or merely the weight to be given to the evidence once it is admitted.

The SCC concluded that the dominant approach in Canadian common law is to treat independence and impartiality as bearing not just on the weight, but also on the admissibility of the evidence. The SCC recognized that expert evidence should be ruled inadmissible if the expert is not impartial, in the sense that he or she cannot objectively assess the questions at hand; or if the expert is not independent, in the sense that he or she provides evidence that is not the product of his or her independent judgment, uninfluenced by who has retained him or her or by the outcome of the litigation.


The SCC fit the independence and impartiality analysis into the established framework for considering the admissibility of evidence.

The admissibility of expert evidence is considered in two stages. First, a court decides whether an expert’s opinion evidence should be admitted based on the four factors laid out in R. v. Mohan: whether the evidence is from a properly qualified expert, relevant, necessary to assist the trier of fact, and not affected by an exclusionary rule. Second, the court exercises its residual discretion to act as a “gatekeeper” and weigh the costs and benefits of admitting the expert’s evidence.

The SCC held that the expert’s duty of independence and impartiality are best addressed first in the “qualified expert” element of the Mohan framework on the basis that an expert unable or unwilling to fulfil the duty of independence is not a properly qualified expert. However, a court must still take concerns about the expert’s independence and impartiality into account when weighing the evidence at the second “gatekeeping” stage. The court must be satisfied that the potential helpfulness of the evidence is not outweighed by the dangers of admitting partisan expert evidence.


The SCC went on to consider what standard of impartiality and independence must be met for expert evidence to be admissible.

The SCC held that if an expert’s duty to provide fair, objective, non-partisan evidence is not challenged, then the expert’s evidence will be admissible upon attestation or testimony that the expert recognizes and accepts that duty. Once the expert has provided this affirmation, the burden is on the party opposing the admission of the expert’s evidence to show there is a “realistic concern” that the expert is unable and/or unwilling to comply with his or her duty to provide fair, objective, non-partisan evidence. If the opposing party meets this burden, then the party adducing the evidence has the burden of establishing, on a balance of probabilities, that the expert is able to provide fair, objective, non-partisan evidence. If the party adducing the evidence cannot meet this burden, then the expert’s evidence—or the parts of the expert’s evidence tainted by a lack of independence or impartiality—should be ruled inadmissible.

The SCC clarified that this first “qualified expert” threshold is “not particularly onerous” and that it will “likely be quite rare” for a proposed expert’s evidence to be ruled inadmissible for failing to meet it. If there are lesser concerns about the expert’s independence, those concerns can be taken into account at the second “gatekeeping” stage. The SCC confirmed that it is the nature and extent of the expert’s interest in or connection with the litigation that is relevant to this inquiry. The mere fact that an expert has some interest in or connection with the litigation will not automatically lead to his or her disqualification. For example, an employment relationship with the party calling the evidence is insufficient to automatically disqualify an expert. However, if an expert has a direct financial interest in the outcome of the litigation, if an expert will probably incur professional liability if his or her opinion is not accepted, or if an expert has a close familial relationship with one of the parties, then his or her opinion evidence is more likely to be ruled inadmissible either at the first “qualified expert” threshold or at the second “gatekeeper” stage.


The SCC’s decision in White Burgess provides important guidance to parties adducing expert evidence and expert witnesses. Expert evidence may be ruled inadmissible if an expert is found not to be independent and impartial. While exclusion of expert evidence at the threshold stage should only occur in “very clear cases”, it is more likely where an expert witness has a close familial relationship with a party, a direct financial interest in the outcome of the litigation, a risk of professional liability if his or her opinion is not accepted, or if the expert assumes the role of advocate for a party. However, these categories are not closed, and experts and parties must remain vigilant to watch for circumstances that compromise independence and impartiality.