Preparing an expert witness for trial

By: Dale Orlando, McLeish Orlando LLP

Published in: Insurance Lawyer Magazine

on October 13, 2013

In a court action for damages arising out of an injury, judges and juries will rely upon the opinions of health professionals in order to understand and interpret the facts of a plaintiff’s claim. However, many health professionals are understandably hesitant to express their opinions within this context. This article is intended to assist health professionals in this regard, through a discussion of what a health professional may expect and how best to prepare, if called to appear as a witness at trial.

The scope of the expert’s testimony

When an expert takes the stand at trial, he or she will not be narrowly confined and limited to the precise content of his or her report, which would have been delivered pursuant to theEvidence Act. A medical expert has a right to explain, amplify and expand on what is latent in the medical report – so long as they are not opening a new field. The purpose of the rule is to facilitate orderly trial preparation by providing opposing parties with adequate notice of opinion evidence to be adduced at trial. The trial judge must be afforded a certain amount of discretion in applying the rule, with a view to ensuring that a party is not unfairly taken by surprise by expert evidence on a point that would not have been anticipated from a reading of an expert’s report.

Taking the stand

The vast majority of civil cases settle before going to trial. However, approximately 1 in 20 cases actually see the inside of a courtroom. If you are called to testify at a civil trial, there are several things that you will need to know in order to properly prepare yourself for your testimony.

Examination in Chief:  The party who calls you to testify as an expert witness at trial conducts what is known as an examination in chief. The rules of evidence require the lawyer who examines in chief to ask open-ended, non-leading questions in areas of contention. The lawyer is permitted to ask closed-ended or leading questions in areas where there is little or no dispute.

The lawyer examining in chief will begin the examination by qualifying you as an expert witness. Since you are testifying not only to facts that are known, but to ready-made inference that can be drawn from those facts, your credibility as a witness will depend significantly on the strength of your professional credentials. It is customary to provide the trial judge with a copy of your professional curriculum vitae so that he or she can follow along during the qualification phase of your testimony. At the conclusion of the qualification phase of your testimony, your curriculum vitae will be marked as an exhibit in the trial.

During the qualification stage of your testimony, you will be asked about your education and training, including where you attended school and when you became registered in your field. Additionally, specialized training should be specifically mentioned during the qualification stage of your testimony. You will be asked about teaching positions held, as well as memberships in professional associations and organizations. You will also be asked about publications and lectures given. Lastly, the examiner will take you through your professional work history.

Once the judge has accepted your qualifications and has qualified you as an expert witness, you may begin giving opinion evidence based on the facts and information received. During this phase of your testimony, you will be asked to provide a detailed list of information reviewed, a summary of the results of any tests given, as well as a summary of the history given by the patient. You will then be asked to provide a summary of any treatments given to the patient. Following that, you will be asked for your diagnosis, your prognosis, and, if applicable, your opinion on causation.

In order to prepare for this phase of your testimony, you should make sure that you can accurately spell and define the technical terms that will be used in your testimony. You should make sure that any definition that you provide is consistent with technical dictionaries, encyclopedias, and authoritative texts, as these are points that may be used in an attempt to embarrass you during your cross-examination. You should familiarize yourself with the most recent editions of standard authoritative texts and other well-known related publications, as you may be cross-examined on these sources of information.

Cross-examination of the expert witness:
 During cross-examination, the examiner will ask closed-ended or leading questions that are designed to elicit reluctant agreement without explanation. A leading question is a question that can be answered with a “yes” or “no”. However, the cross-examiner will prefer a positive response.During the course of your evidence in chief, you must be careful only to answer the questions asked, and not delve into areas that are outside of your particular expertise. Whenever possible, lay terms and language should be used, particularly when testifying in front of a jury. Visual aids should also be used whenever possible to assist the trier of fact in understanding the evidence.

There are numerous objectives to cross-examination, depending on the case. Some of the objectives of cross examination are as follows:

Expose the expert’s bias: A testifying health provider should be prepared to be subtly, or not so subtly, accused of being biased in favour of the party that calls them as a witness. There are a number of ways this can be done. First, if the expert frequently gives opinions for one side over the other (for example, the defence as opposed to the plaintiff) and frequently gives the same opinion, this will be exploited. Second, if the expert frequently gives an opinion for a particular law firm, this will be brought to the attention of the jury. And third, if the expert makes a great deal of money from report writing and testifying, this is an opportunity that will not be forgone. This area of cross-examination will be approached with caution. Just because a witness gets paid for their time does not mean his opinion is up for sale. However, a witness who spends a disproportionate amount of time in court and who charges large fees is vulnerable to attack.

Destroy the factual underpinnings upon which the opinion is based: This type of cross-examination works well when an expert has not been given all of the facts or when some of the facts being relied upon by the expert have been shown to be inaccurate. The expert will have to acknowledge that the opinion being offered is based upon numerous facts relied upon, and if the facts are incorrect or incomplete, the opinion offered may be undermined. The examiner will point out the various facts that the expert was not aware of or that are incorrect. The examiner may not even ask if the new facts or corrected facts change the expert’s conclusions, but rather, let the jury reach their own conclusion based upon an impression that the expert’s opinion was built upon a faulty factual foundation.

The cross-examiner may try to impeach the expert through the use of leading authorities. According to McElhaney’s Litigation “If an expert differs with published authors in her field, she may be wrong.”

Before this technique can be used, the expert must acknowledge that the text or article was authoritative at the time of the event in question. If you acknowledge an article or text as authoritative, you can be cross-examined regarding the extent that the authoritative text or article disagrees with what you have said on the stand.

Exposing the opinion as a matter of judgment: Another approach is for the cross-examiner to extract from the expert the concession that the issue in dispute is one in which respected, competent professionals disagree, and that the expert’s opinion is a matter of professional judgment only.

Getting the expert to defer to the opposing expert’s superior opinion: There are a number of ways this can be done. First, if you are being called as an expert for the defence and are being cross-examined by the plaintiff’s lawyer on the fact that the plaintiff’s treating health care professional has seen the plaintiff more often than you have, you will have to admit that they had a better opportunity to assess the plaintiff and come to an informed opinion. If you do not, you risk sounding like an advocate for the side that hired you.

Additionally, if the opposing expert has more credentials than you do, you can expect to be cross-examined on this. The opposing expert may have been a teacher of yours or may have written more articles.


There are a number of reasons why you may be wary of providing your professional opinion for the purposes of a court action, ranging from a lack of confidence in your knowledge of legal proceedings, to a fear of being embarrassed on the witness stand. This article has provided a broad overview of the role of the expert witness, but there is no substitute for experience. If you are going to be providing expert evidence in Court for the first time, to truly  prepare, you should attend at your local courthouse and observe competent counsel conducting a trial of issues similar to the case for which you will be called to testify.

Dale Orlando is a founding partner in McLeish Orlando and past president of the Ontario Trial Lawyers Association, practicing exclusively in the area of plaintiff’s personal injury litigation. He can be reached at

Dale Orlando


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