Trial Issues

• Author: Eric V. Gottardi/Jennifer A. MacLellan/Michael Lacy/Robin Flumerfelt
• Pages: 65-90

65

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Trial Issues

I. To Qualify or Not ......................................... 66

A. Lay Opinion ........................................ 66

II. Qualifying the Expert ...................................... 67

A. Defining Scope and Creating Clarity .................... 68

B. Test for Qualification as an Expert Witness ............... 68

C. Problems with Qualification ........................... 70

III. Direct Examination of the Expert Witness ...................... 71

A. The Expert’s Report .................................. 72

IV. Cross-Examining the Expert ................................. 72

A. Contexts for Cross-Examination ........................ 75

V. Jury Instructions .......................................... 88

VI. Conclusion .............................................. 90

© [2022] Emond Montgomery Publications. All Rights Reserved.

66 Part I Principles and Procedure

I. To Qualify or Not

Not every witness with expert qualifications must be qualified as an expert before

testifying in court. Consideration must be given to whether the witness will give an

opinion or simply testify to factual observations. As stated in R v K (A):

The line between fact and opinion must therefore be kept clearly in mind. A witness, who

is an expert in a particular field, may be called simply to give evidence on the facts he or

she has observed without offering an opinion based on those facts. To that extent, and if

otherwise admissible, this evidence is not subject to the opinion rule. This would be the

case, for example, where a treating physician is called to describe the injuries he or she

observed on a patient without offering any opinion on the matter. It is only when a witness

purports to give an opinion on certain facts that the opinion rule comes into play. If, in our

example, the treating physician goes on to say that it is usual or unusual, as the case may

be, to observe this kind of injury in a patient who alleges that sexual intercourse has taken

place, the witness is offering opinion evidence and the evidence will be subject to the

general rule of exclusion. It will only be admissible if certain established criteria are met.1

However knowledgeable a factual witness may be, they should not be asked for an

opinion. In Compton v Toyota Canada Inc, the Newfoundland Court of Appeal rejected

a separate category of the “very knowledgeable fact witness.”2

On the other hand, in R v Hamilton, the Ontario Court of Appeal held that even

when the evidence in issue is associated with the witness’s profession, it is not ne-

cessarily an expert opinion if it is merely a recitation of uncontroversial facts (in that

case, about the operation of cellphone networks).3

An expert witness qualified by the court can give both factual and opinion evidence.4

However, if the determination is made to forgo qualifying a witness as an expert, that

witness cannot be asked for an opinion based on their expertise.5

A. Lay Opinion

There are some situations in which the court will accept a lay opinion from a witness,

but they are circumscribed. As stated in Compton:

There is a significant distinction between lay opinions and expert opinions. Expert

opinions are informed by the expert’s special expertise, while lay opinions need not be

1 R v K (A), 1999 CanLII 3793, 45 OR (3d) 641 (CA) at para 72; see also R v Panghali, 2012

BCCA 407.

2 2019 NLCA 79 at para 90.

3 2011 ONCA 399 at paras 277-80; see also R v Ajise, 2018 ONCA 494, aff’d 2018 SCC 51.

4 R v McPhail, 2019 ABCA 427 (“[a]n expert is also entitled to give factual evidence of personal

observations, outside the rules regarding the admissibility of expert evidence” at para 4).

5 JP v British Columbia (Children and Family Development), 2017 BCCA 308 at paras 186, 227,

leave to appeal to SCC refused, 2018 CanLII 11146.

© [2022] Emond Montgomery Publications. All Rights Reserved.