Expert Witness Report:

Question: What should Ontario litigators and proposed expert witnesses include to prepare an admissible expert witness report for court?

Answer: Legacy Legal Services can help legal professionals and proposed expert witnesses in Ontario understand the requirements for an expert witness report that is more likely to be admitted and relied upon by the court, including meeting the R. v. Mohan criteria, being properly qualified, and clearly linking the opinion to the evidence through a readable, proofed, well-referenced structure with appendices, bibliography, and defined terminology, while also avoiding biased wording and unnecessary criticism of other experts.   To reduce the risk of an inadmissibility challenge, get the report scope confirmed with counsel, use professional formatting (cover page, index, headings, clear summaries, and consistent page and appendix references), and ensure the expert’s conclusions reflect an unbiased view grounded in authentic reasoning.   If you need to prepare or tighten an expert report for litigation in Ontario, call (226) 246-3825 to discuss your matter with Legacy Legal Services.

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

A proper, well crafted, expert witness report can make the difference between success or failure within a lawsuit; and accordingly, avoiding mistakes within an expert report is of utmost importance so to ensure that the expert report is admissible, and may be relied upon, within the court proceeding. If an expert report is deemed inadmissible, such may jeopardize the legal case.

The Law

Admissibility

For a court to admit an expert report as evidence the expert report must meet the criteria of admissibility.  The criteria was summarized within the case of 2599475 Ontario Inc. v 2549445 Ontario Inc., 2023 ONSC 3508, where it was said:

Quality Expert Reports

Communicate Clearly and Effectively

Before the work of preparing a report begins, the expert should obtain a clear and concise understanding of the scope of detail required within the report by communicating directly with the lawyer or paralegal who is seeking the report from the expert; whereas, depending on the nature of the litigation, the required statements within the report may vary between just a general summary expert viewpoint or a highly detailed expert opinion. Failing to conduct this review may result in the expert wasting the effort of preparing an excessively detailed report or useless preparing an insufficient report; and whereas both possibilities may result in a waste of time, such is also a waste of money.

It is also necessary that the supporting evidence documents reviewed by the expert are adequately included and properly referenced.  The expert opinion contained within a report should, and perhaps must, refer to supporting evidence documents such as pictures or testing results, among other things, attached as appendices or schedules.  Additionally, a bibliography to summarize any authoritative documents used for research should be included.

The report should read clearly with ease and appear professional and proofed for proper spelling, grammar, and punctuation.  The expert should write in a style directed towards the intended audience, balancing need that the report be understood by an average layperson without belittling highly intelligent judges and lawyers or other experts.  Reports should omit or limit industry specific jargon and abbreviations; but, if such is necessary, include definitions 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

An expert report must be impartial and objective.  The role of an expert is to provide an unbiased opinion to the court for the purpose of aiding in the truth-seeking mission of the court.  The expert must therefore ensure that the expressed opinion is grounded in facts and evidence rather than prepared with a favouring 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.