The Supreme Court recently denied leave to Appeal the Ontario Court of Appeal’s decision in Westerhof v. Gee, leaving the Court of Appeal’s decision as the final word on the important issue of the application of Rule 53.03.

The case unfolded on the distinction made between experts retained for the purposes of litigation (“litigation experts”) and those experts who are not. Examples of those experts not retained for the purpose of litigation include treating physicians (“participant experts”) and experts in the Accident Benefit context (“non-party experts”). Specifically, the issue in the case was whether Rule 53.03 requires that “participant experts” or “non-party experts” must render expert reports, before such experts are allowed to testify.

The Westehof case was a typical MVA personal injury action. It was tried after the important 2010 amendments to the Rules, which were about ensuring the neutrality of expert witnesses and the adequate disclosure of the basis for experts’ opinions. The amendments were enacted in part to address the common complaint outlined in Honourable Coulter Osborne’s report that “too many experts are no more than hired guns who tailor the reports and evidence to suit the client’s needs.”

In Westerhof, the trial judge refused to allow several participant expert and non-party expert witnesses to provide opinion evidence concerning history, diagnosis and prognosis of Mr. Westerhof’s injuries. Specifically, Mr. Westerhof’s treating chiropractor, psychiatrist and physiotherapist, among others, were prevented from giving evidence of the history they had taken from Mr. Westerhof. 

Mr. Westerhof appealed to the Divisional Court. In dismissing Mr. Westerhof’s appeal, the Divisional Court held that the “important distinction is not in the role or involvement of the witness, but in the type of evidence sought to be admitted”. If the evidence at issue is opinion evidence, then compliance with rule 53.03 is required; if the evidence at issue is factual evidence, then compliance with rule 53.03 is not required.

The Court of Appeal did not agree with the Divisional Court’s conclusion that the type of evidence – whether fact or opinion – was the key factor in determining to whom rule 53.03 applies. The Court of Appeal held that an expert who was not engaged for purposes of litigation can give opinion evidence without compliantce with Rule 53.03, when two conditions are met:

  • the opinion to be given is based on the witness’s observation of or participation in the events at issue; and
  • the witness formed the opinion to be given as part of the ordinary exercise of his or her skill, knowledge, training and experience while observing or participating in such events.

Despite its ruling, it is important to note that the Court of Appeal still emphasized the role of the Court as gatekeeper in relation to opinion evidence, noting that, for example, “The court could also require that the participant expert or non-party expert comply with rule 53.03 if the participant or non-party expert’s opinion went beyond the scope of an opinion formed in the course of treatment or observation for purposes other than the litigation.”

In conclusion, the Court of Appeal’s final word on the issue injected some much needed flexibility into the admissibility of evidence that can be crucial in personal injury actions.