Gaining Access To Experts' Foundational Materials

• Published date: 15 September 2020
• Law Firm: McLennan Ross LLP
• Author: Lydia Roseman

Background

The disclosure of expert reports and their supporting data is a widely litigated area.

The jurisprudence in all Canadian jurisdictions is fairly consistent that a party is entitled to the foundational or underlying material of an opposing party's expert report at some point. As stated by the Supreme Court, "the opposing party must be given access to the foundation of [expert] opinions to test them adequately".¹ This disclosure requirement applies even to factual underpinnings that the expert had in its possession but did not actually use in creating its ultimate report.²

The dividing issue when it comes to the factual underpinnings of expert reports is when they must be produced. Some courts and jurisdictions consider production required when an expert report is served, for others it is only when the report is entered at trial or the expert is called to testify.

The Rule

Recent Alberta jurisprudence generally only requires production of underlying materials to expert reports once the report has been entered at trial or the expert has been called to testify.

This is a departure from previous case law and from the jurisprudence in most other jurisdictions.³ Older Alberta jurisprudence under the previous Alberta Rules of Court generally held that once an expert report is served, privilege is waived and the opposing parties are entitled to the underlying materials.

Under the previous rule, Rule 218.1, the party was required to serve a copy of the expert report including "the substance of his opinion". In a 1985 decision, the Alberta Court of Queen's Bench concluded that the substance of the opinion includes not only the opinion but the factual information upon which that opinion is...