Canada: Expert Evidence – "The 7 Deadly Sins" #2 – Trying To Fit Square Pegs Into Round Holes

Last Updated: August 4 2012
Article by Errol Soriano

The courts have been consistent and clear that expert evidence is permissible to assist in limited circumstances. In the seminal case R. v. Mohan:1

"Admission of expert evidence depends on the application of the following criteria:

(a) relevance;

(b) necessity in assisting the trier of fact;

(c) the absence of any exclusionary rule; and,

(d) a properly qualified expert."

and in Rice v. Sockett:2

"The derivation of the term 'expert' implies that he is one who by experience has acquired special or peculiar knowledge of the subject of which he undertakes to testify, and it does not matter whether such knowledge has been acquired by study of scientific works or by practical observation. Hence, one who is an old hunter, and has thus had much experience in the use of firearms, may be as well qualified to testify as to the appearance which a gun recently fired would present as a highly-educated and skilled gunsmith."

If the relevance, necessity and expertise of the expert are not established and precisely communicated to the court during the qualification process, the range of the expert's subsequent testimony may be restricted by sustained objections from opposing counsel, leaving you with an unplanned void in the evidentiary foundation of your case.

Trouble is not far off if:

1. The right questions are asked, but to the wrong expert; or,

2. The right expert is asked to give an opinion on the wrong questions/issues.

Trouble can come in three principal forms:

1. Ill-conceived Marching Orders

In several cases, I have been faced with a series of cross examination questions regarding an instruction letter I received – an avoidable distraction;

On the surface, informing the expert as to the mandate, and the substance and timing of deliverables seems relatively straight forward, and in years gone by this was probably true. But in today's environment of more fulsome disclosure, the expert's file (including communications with counsel) may be available to opposing counsel at some point in the proceedings. It is important to keep this in mind during all your dealings with your expert.

Initial instructions and subsequent communications between counsel and the expert can be verbal or written and general or detailed.

A more general mandate may involve, for example, a brief discussion over the phone whereby the expert is asked to provide his/her opinion as to the "financial loss" in the matter. A detailed mandate may ask the expert to provide an opinion on specific questions posed by counsel to the expert.

Detailed questions are appropriate in some cases, particularly when there are specific/discreet issues in dispute which have a qualitative financial component. A few words of advice:

a) Do not wander into issues that are within the domain of the trier of fact (i.e. the ultimate issue);

b) Do not couch the instruction letter with loaded terminology – the instruction letter is not argument. An independent expert should ignore such positioning but that doesn't mean it won't be an area of cross examination; and,

c) Avoid unnecessary narrative in the instruction letter – this adds nothing to the effectiveness of the communication.

2. Qualifying the Expert at Trial

The qualification process is an important element in presenting expert evidence. However, how many times have you seen counsel stumble when qualifying an expert during court proceedings? Business valuators described as accountants (which is not necessarily wrong, but is not precise), accountants described as actuaries (wrong on any measure) and actuaries described as economists; or a long pause when attempting to describe what the expert's mandate involved.

It is not a great way to start an Examination in Chief, particularly if your expert has a pension for precision and starts to correct you in real time during his/her testimony.

The problem often stems from the fact that, on occasion, counsel may have only briefly considered the questions to pose to qualify the expert.

Planning the qualification process has never been more important than in today's environment with the courts' greater emphasis on the gatekeeper role evidenced in recent decided cases. This role was explained in one recent case as follows:

"When assessing the qualifications of a proposed expert, trial judges regularly consider factors such as the proposed witness's professional qualifications, her actual experience, her participation or membership in professional associations, the nature and extent of her publications, her involvement in teaching, her involvement in courses or conferences in the field and her efforts to keep current with the literature in the field and whether or not the witness has previously been qualified to testify as an expert in the area."3

And in the Inquiry into Pediatric Forensic Pathology in Ontario (2009) in which Justice Goudge wrote "The proper practice is for counsel presenting an expert witness to qualify the expert in all the areas in which the expert is to give opinion evidence. If this is done, no question as to the admissibility of their opinions arises."4

Often times opposing counsel will rise during the qualification process to announce that the tendered expert's suitability is conceded – don't forego the rest of the questions in the qualification process – use this opportunity to establish the expertise and credibility of the witness.

3. Stretching and Encroachment

Litigation cases are often complex and require several years to resolve. As a result, it is not uncommon that the issues in dispute evolve over time and this may require adjustments to the expert's mandate. It is important to evaluate the evolving nature and purpose of the required expert evidence, and assess whether the current expert:

a) is qualified to provide the new opinion;

b) has prepared opinions either in this case or in other cases that can have an impact on his/her ability to render the (new) required opinion in this case.

Most importantly, don't let the expert opine on issues that are the purview of the court. Don't fit square pegs into round holes.

"The objection to expert opinion evidence is often framed, incorrectly, as a prohibition against adducing evidence on the ultimate issues in a case. In the text by Sopinka, Lederman and Bryant, The Law of Evidence in Canada, (1992) at p. 540, it is noted that the closer the testimony of an expert gets to the ultimate issue the court has to decide, the more inclined the court is to reject that evidence. The writer notes [sic], however, that while the justification for this prohibition is often said to be that such an opinion would "invade the province" or "usurp the function" of the jury, the preferable rationale is that enunciated by Aylesworth J.A. in Fisher v. R., [1961] O.W.N. 94 (C.A.) at pp. 95-96. It is not because there is encroachment upon the jury's function that expert evidence has been rejected in certain cases, but rather that in those cases the expert opinion was superfluous.5

The issue is further illustrated in the following decision excerpt.

"Mr. [xxx's] report contained as well the following mandates:

To review the bank's procedures and to provide an opinion with respect to the standard of care of the bank's procedures...To provide an opinion with respect to the matter of whether or not the bank adhered to and/or fulfilled all of the terms and conditions of their commitment letter... To provide an opinion with respect to the facts and circumstances leading up to the bank's decision to realize on its security....

"As I expressed in the Schneider trial (approved specifically in the Court of Appeal in Pente Investment Management Ltd. v. Schneider Corp. (1998), 42 O.R. (3d) 177 (Ont. C.A.)) such "expert evidence" is inadmissible. It offends the requirements of R. v. Mohan (1994), 114 D.L.R. (4th) 419 (S.C.C.); specifically it usurps the function of the trial judge. It is for the court to determine the standard of care and whether there has been adherence or breach. The second and third mandates, if presented as expert opinion in court testimony, would seemingly be even more offensive."6


1 29 C.R. (4th) 243, 71 O.A.C. 241, 166 N.R. 245, 89 C.C.C. (3d) 402, 114 D.L.R. (4th) 419, [1994] 2 S.C.R. 9, 18 O.R. (3d) 160 (note) (S.C.C.)

2 [1912] O.J. No. 49, 27 O.L.R. 410 (C.A.), Falconbridge C.J. stated at p. 413 O.L.R.

3 Tavernese v. Economical Mutual Insurance 2009 CarswellOnt 3204

4 Dulong v. Merrill Lynch Canada Inc. 2006 CarswellOnt 1843.

5 In R. v. Abbey, [1982] 2 S.C.R. 24, at p. 42,

6 Toronto Dominion Bank v. E. Goldberger Holdings Ltd. 1999 CarswellOnt 4667 43 C.P.C. (4th) 275

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Check to state you have read and
agree to our Terms and Conditions

Terms & Conditions and Privacy Statement (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

Use of

You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.

Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

If you do not want us to provide your name and email address you may opt out by clicking here .

If you do not wish to receive any future announcements of products and services offered by Mondaq by clicking here .

Information Collection and Use

We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to with “no disclosure” in the subject heading

Mondaq News Alerts

In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

Log Files

We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

Surveys & Contests

From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to

Correcting/Updating Personal Information

If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to

Notification of Changes

If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

How to contact Mondaq

You can contact us with comments or queries at

If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at and we will use commercially reasonable efforts to determine and correct the problem promptly.