Expert Witness Report:

Question: What are the key requirements for an expert witness report to be admissible in an Ontario civil court case?

Answer: In Ontario civil litigation, an expert witness report should address relevance, necessity, and proper qualification, be impartial and evidence-based, clearly explain methods and supporting documents, and use an organized, readable format with clear conclusions; courts commonly apply the framework from R. v. Mohan, 1994 CanLII 80 (SCC) and White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23 when assessing admissibility.   For help coordinating report scope, document support, and court-ready presentation with Paralegals serving clients across Ontario, contact Anderson Aylwin Begg & Co. at (905) 686-8080 for practical guidance that can reduce delays and strengthen your case strategy.

Understanding the Requirements When Preparing an Expert Witness Report Document for Court Litigation Purposes

Various best practice habits when preparing expert reports can help ensure a well-crafted document that is both effective and efficient for use within the courtroom. Indeed, a quality expert report can be the difference in making or breaking a case; and accordingly, the choice of expert, the style of report, and the manner used when expressing expert opinion, require careful review.

The Law

Admissibility

When reviewing whether to admit an expert report as evidence, a court will seek to ensure that the report meets the required admissibility criteria.  Expert evidence admissibility criteria summarized within 2599475 Ontario Inc. v 2549445 Ontario Inc., 2023 ONSC 3508, whereas it was stated:

Quality Expert Reports

Communicate Clearly and Effectively

Prior to drafting a report, the expert should review the required scope of the report with the representative, being the lawyer or paralegal, who seeks the report.  Depending on the nature of the court case, the report may require broad details or may require a narrow focus.  In some circumstances, a brief report is adequate; and in other circumstances a more lengthy report is necessary.  Forgoing this review can result in the waste of preparing an insufficient report or the waste of preparing an excessive report.  Either is a waste of time and therefore money.

A proper expert report includes, and properly references, the evidence documents that support the expert opinions and conclusions.  The evidence documents can, and should, include pictures, study data, testing results, among other details, all provided as attached appendices or schedules.  A bibliography referencing any authoritative documents or studies that are used to support opinions and conclusions should also be included.

An expert report should express opinions clearly and concisely while being easy to read in an organized and professional layout with spelling, grammar, and punctuation, carefully reviewed for correctness.  The expert report should be written with a vernacular and tone that is consistent with the language of the intended audience whereas, for example, differences may be required for legal cases heard by a judge versus legal cases heard by a jury; and accordingly, language should remain within the understanding of the average layperson while avoiding belittlement of judges, lawyers, and other experts.  Reports should be careful to limit the use of industry specific jargon or abbreviations known only to those with expertise within the relevant field; and, where industry jargon or abbreviations are necessary, a reference table or key to provide definitions should be provided within the report.

More Hints

• Use professional letterhead;
• Use a cover page as well as an index or table of contents;
• Use a curriculum vitae or resume to summarize the qualifications and credentials that confirm that the expert is genuinely an expert;
• Use an introduction page to outline when, and from whom, the report was requested;
• Use 12-point font and double spacing;
• Use headings;
• Use short, concise paragraphs;
• Use a unique reference number for each page, table, chart, and appendix;
• Use a definitions page or section to define technical language and industry specific jargon or abbreviations; and
• Use an upfront summary page to outline final conclusions or opinions.

Things to Avoid

A biased or slanted expert report can be disastrous – and should be!  The expert is expected to provide opinion as a friend of the court for the primary purpose of assisting the court in the truth finding effort.  The expert, while having an opinion that may favour one litigant over another, must base the opinion on authentic reasons rather than as friend of a litigant.

• Avoid absolute wording and phrasing;
• Avoid words that appear as hedging or guessing;
• Avoid critical commentary regarding credibility of other experts;
• Avoid a scientific and clinical tone by keeping the tone friendly and personable;
• Avoid going into details beyond the purpose of the report;
• Avoid unnecessary adjectives or superlatives.

Summary Comment

The expert preparing an opinion report must remain attentive to the balance required when obtaining input from a legal representative whereas the lawyer or paralegal seeking the report will best understand the factual concerns and legal issues that relate to why the report is needed and can explain the desired scope; however, the findings and opinions as stated within the report must always remain the genuine unslanted view of the expert as author of the report.