519 672 2121
Close mobile menu

Litigation is complicated. There are many rules, procedures and bureaucratic hoops you need to jump through to get your day in court. Hiring competent lawyers to help you resolve your legal issue is by far the best way to navigate this complicated system.

Civil litigation specialists are familiar with the rules that govern the litigation process from start to finish. These rules are called the Rules of Civil Procedure.1 Each province has their own version of the Rules. In Ontario, there have been some big changes to the Rules that impact the way civil cases are managed.

On March 31, 2022, several rule changes will take effect regarding the use of expert evidence at trial. Parties rely on experts like doctors, engineers, and accountants to help explain their case to the Court. For example, doctors often give expert opinions about the injuries sustained by a Plaintiff in a personal injury action. Engineers might reconstruct an accident and give evidence about the mechanism of the accident, which might help the court determine who was at fault. Accountants calculate the past and projected income loss of someone who is no longer able to work in the same capacity as they could before an accident. There are many other types of experts and they play a vital role in helping the judge find a reasonable and fair result.

To call an expert to give evidence at trial, parties must comply with the rules governing expert evidence set out in the Rules of Civil Procedure. These rules exist to ensure that expert evidence is fair, balanced, and impartial. They also set out a timeline for exchange of expert reports so that each party has an opportunity to respond to the other’s experts in advance of trial.

The new rules provide serious consequences for failing to serve expert reports within the timelines mandated by the rule. A party failing to follow this new rule risks a Court ignoring this often important and necessary evidence.

Rule 53.03 – Expert witnesses

When a party wishes to use an expert to give opinion evidence at trial, the expert must comply with Rule 53.03 of the Rules of Civil Procedure.

The proposed expert must prepare a report with specific information included, and swear an acknowledgement of expert’s duty (Form 53) promising that any evidence provided would be fair and impartial. The expert’s report must include:2

  1. The expert’s name, address and area of expertise.
  2. The expert’s qualifications and employment and educational experiences in his or her area of expertise.
  3. The instructions provided to the expert in relation to the proceeding.
  4. The nature of the opinion being sought and each issue in the proceeding to which the opinion relates.
  5. The expert’s opinion respecting each issue and, where there is a range of opinions given, a summary of the range and the reasons for the expert’s own opinion within that range.
  6. The expert’s reasons for his or her opinion, including,
    • a description of the factual assumptions on which the opinion is based,
    • a description of any research conducted by the expert that led him or her to form the opinion, and
    • a list of every document, if any, relied on by the expert in forming the opinion.
  7. An acknowledgement of expert’s duty (Form 53) signed by the expert.

Timeline for exchange of expert reports

The parties are to provide the signed expert reports to the other side under specific timelines to ensure that each party has the opportunity to know what expert evidence the other intends to rely upon at trial.

A party who intends to call an expert witness at trial must provide the expert report at least 90 days before the Pre-Trial conference.

The Pre-Trial is a conference with a judge to review the case, attempt settlement, and sort out any outstanding trial scheduling matters. It must be held at least 90 days before the trial start date.

If the other party wishes to call an expert to respond to the original expert report, they must provide their expert report at least 60 days before the Pre-Trial Conference. The parties are also able to agree to a different timeline for service of expert reports between themselves.

The problem with late served expert reports

Previously, if one of the parties did not comply with the timeline for service of expert reports, the other party was the one that suffered the consequences. For example, if the Defendant did not serve their expert report until after the Pre-Trial conference, there was a good chance that the Plaintiff would not be able to get a responding report completed in time before the trial started. The Plaintiff would either have to try to proceed through trial unable to respond to the Defendant’s expert evidence, or the trial would be adjourned to give the Plaintiff more time to get a responding report.

The trial judges’ hands were tied: they had to admit the late served expert evidence, or adjourn the trial.

The civil justice system is incredibly backed up and the Covid-19 pandemic has not helped matters. An adjournment of a trial could mean another year or more of waiting for the matter to be heard in court. This outcome was hardly fair to the party who complied with their disclosure obligations and caused no end of headaches to the judges trying to move these matters along.

The recent solution to the problem

The recent rule changes are an effort to address this unfairness.

Now, Rule 53 expands the powers of the Pre-Trial and Trial judges to deal with late served expert reports. The Pre-Trial Judge can extend or abridge the timelines for service of expert.3 The timeline can also be altered through a motion brought before the Court or with the written consent of the parties.

The biggest change are consequences for failing to comply with the timeline for delivery of expert reports. Under Rule 53.08, if a party is late serving an expert report, that expert evidence is admissible with leave of the trial judge only if the defaulting party satisfied the judge that:4

  1. There is a reasonable explanation for the failure; and
  2. Granting leave would not,
    • Cause prejudice to the opposing party that could not be compensated for by costs or an adjournment, or
    • Cause undue delay in the conduct of trial.

We will have to wait for the new rules to take effect to understand what will be accepted as a “reasonable explanation for the failure”.

Additionally, Rule 50.12 expands the powers of the Pre-Trial judge to include the ability to order costs against a party who wasted the Pre-Trial Judge’s time by not being ready. The parties cannot have meaningful settlement discussions if one party has not obtained the necessary expert opinions. The Pre-Trial judge can now order the defaulting party to pay costs to the other side for wasting everyone’s time at the Pre-Trial.


If you need an expert to give opinion evidence at trial, they must complete an expert report that complies with Rule 53.03. The report must be served on the other side at least 90 days before the Pre-Trial. Responding reports must be served at least 60 days before Pre-Trial. Failure to meet these deadlines could mean paying costs to the other side at the Pre-Trial, and/or the Trial Judge refusing to hear evidence from your expert.

Hopefully these rule changes will lead to timely resolution of these matters and improve trial fairness going forward.

The lawyers at Siskinds are experts at navigating the Rules of Civil Procedure to help out clients reach a timely, fair and just resolution of their civil matters.

Victoria Edwards practices with the Siskinds Personal Injury department. If you have any questions about the information contained within this article or any other personal injury questions, please write to [email protected] or call her direct line 519-660-7848.

1 Rules of Civil Procedure, R.R.O. 1990, Reg. 194

2 Rule 53.03

3 Rule 53.03(4)

4 Rule 53.08

News & Views


The more you understand, the easier it is to manage well.

View Blog

Civil Motions in the Superior Court of Justice: A Practical Guide for Junior Lawyers

Practical tips for bringing and speaking to motions in the civil Superior Court of Justice i…

The dangers of drip pricing: Shining a spotlight on hidden fees

When a consumer chooses to make a purchase based on a price displayed, they should be able t…