MLJ Volume 36-1.pdf - Robson Hall Faculty of Law

The Trial Judge's Four Discretions 157
first noted problem. This would elevate (as it were) a common law general
discretionary power to the level of statutory law, in effect creating a new
form of exclusionary discretion which could overcome the clear statutory
dictates of section 12. The lead opinion 58 endorsed La Forest J’s
characterization of the exclusionary discretion as being derived from the
common law by virtue of the decision in Wray, and as continuing to
subsist since the language in section 12 did not expressly abolish it. 59 In
the view of a majority of the Justices, this absence meant that the section
would have to be read as leaving room for the common law discretion to
operate, albeit in a new and superior form, in order that a “fair trial” could
be ensured for the accused. This interpretation of section 12 would
minimize the violence done to the doctrine of parliamentary supremacy
feared by McIntyre and Le Dain JJ, because there was no question that
section 12 failed to indicate that the exclusionary discretion possessed by
the trial judge should be removed, though clearly the Supreme Court’s
interpretation was elevating the common law principle recognized in Wray
to a new stature, that of statutory law.
What is more, the balancing exercise by which the discretion existing
within section 12 of the Canada Evidence Act was said to operate, namely a
balancing of prejudice against probative value, was a departure from the
Wray standard, which only allowed for the exclusion of admissible
evidence where its probative value was low, and its prejudice very high. 60
As La Forest and Dickson JJ (concurring) stated in Potvin (albeit in the
context of the statutory discretion contained in section 715 of the Criminal
Code) trial judges may exclude evidence under this discretion even if its
probative value is more than modest. 61 This new balancing exercise was
also a harbinger of things to come in terms of the scope of the common
law exclusionary discretion, which would come to embrace the same
exercise. It is clear that the exclusionary discretion existing within section
12, unlike the Wray formulation, can exclude evidence even where the
strict requirements for exclusion noted in Wray are absent. 62 This seems to
58
Corbett, supra note 2 at 697.
59
Corbett, supra note 2 at 730, per La Forest J (dissenting).
60
R v Richard (1980), 56 CCC (2d) 129 at 136, 25 BCLR 29 (BC CA) [Richard]
(describing the standard by which the Wray discretion operates).
61
Potvin, supra note 24 at 532.
62
See Section III-A below for an explanation of the restrictive tripartite standard that