The Ontario Superior Court has provided us with further clarification on the admission and qualification of participant and litigation experts. Back in 2019, we blogged on this same issue, but the decision Snodden v 2568832 Ontario Inc, 2023 ONSC 6759 has provided an updated analysis.

Under Rule 53.03 of the Rules of Civil Procedure a party who intends to call upon an expert witness to provide opinion evidence before the Court must comply with several rules with respect to the timing and service of reports, the contents of these reports, and the qualifications of the expert. However, the Ontario Court of Appeal in Westerhof v Gee Estate, 2015 ONCA 206, held that in certain circumstances "participant experts" may also provide limited opinion evidence without having to comply with these rules.

The two considerations laid out in Westerhof for determining whether a participant expert may give opinion evidence were:

  1. Is the opinion to be given based on the witness' observations of, or participation in the events at issue?
  2. Did the witness form the opinion to be given as part of the ordinary exercise of his or her skill, knowledge, training, and expertise while observing or participating in such events?

Justice Woodley in the Snodden decision added an additional consideration:

  1. Whether the person has been engaged by or on behalf of a party to the litigation;

If a witness satisfies these requirements, they are known as a participant expert and are qualified to give opinion evidence without complying with Rule 53.03. However, if any of the considerations point towards the proposed expert being a Rule 53.03 expert, the witness may not provide opinion evidence without first being qualified pursuant to Rule 52.03 and the supporting caselaw.

We will next break down the analysis of each of these factors:

  1. Was the proposed witness engaged by or on behalf of a party to the litigation?

If yes, they may not be a participant expert. In answering this question, the court will consider:

  • Was the witness retained prior to the commencement of the litigation?
  • Was the report prepared prior to the commencement of litigation?
  • Who retained the witness? Are they a party to the action?
  • What is the purpose of their report? To give an opinion about who was responsible for the tort?

Justice Woodley also clarified that the submission that the report is not a Rule 53.03 report because it is referred to as a "preliminary report" is rejected.

  1. Did the proposed witness base their opinion on their personal observations of or participation in the events at issue?

In order to be considered a participant expert, the trier of fact must be convicted through the evidence that the witness attended the site or scene in question and "participated" in the events in issue. The court will ask: is the involvement of the witness limited to the receipt and review of information and documents compiled by third parties? If yes, that is insufficient to be considered "participation".

Justice Woodley equates the level of involvement required to be that of a treating physician or surgeon engaged as a participant expert due to an illness or injury caused by a third party. Or that of a fire inspector who attends to inspect a site as the result of their duty and professional obligations.

A "classic Rule 53 expert", as Justice Woodley puts it at paragraph 22 of the Snodden decision, is someone who is "provided with information and documents and prepare[s] his opinion based on his review and observations of second-hand information", including photographs referenced in a report. The fact that an expert did not take any of the photographs included in their report points to the lack of the expert's personal participation in the events. Such photos are not "personal observations" sufficient to render an individual a participant expert.

  1. Was the formation of the opinion done in the ordinary exercise of the expert's skill, knowledge, training, and experience while observing or participating in the events?

This question is touched on very briefly by Justice Woodley. The conclusion being that while a proposed expert can clearly be an expert within their field, if there is no evidence before the court that the opinion they have drawn was formed "while observing or participating in the events", they may not be qualified as a participation expert.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.