contextual way. In support of that proposition, Rogers relies on Kerton v. Workers’
Compensation Appeal Tribunal, 2010 BCSC 644 at para. 70, rev’d on other grounds 2011
BCCA 7, where reference is made to Ruth Sullivan, Sullivan and Driedger on the Construction
of Statutes, 4th ed. (Markham, Ont.: Butterworths Canada, 2002) at 58, which states that “the
use of ‘may’ implies discretion, but it does not preclude obligation.”
45] It is important to note that Kerton was not necessarily endorsing the author’s view.
Justice Rice was summarizing the tribunal decision under review, and the tribunal referred to
that text in its decision. In any event, the quote from the text simply notes that the word “may”
could be interpreted as obligatory if something else in the statute or circumstances “expressly
or impliedly obliges the exercise of the power”: Sullivan at 58.
46] Rogers also relies on Appleton & Associates v. Branch MacMaster LLP, 2020 BCCA
87 at paras. 22–23. In those passages, the Court of Appeal for British Columbia notes that the
use of “may” does not mean the discretionary power is unfettered; the court must consider
whether the word “may” is “accompanied by a duty to exercise the given power”: para. 22.
47] These principles are uncontroversial and consistent with the modern approach to
statutory interpretation, whereby “the words of an Act are to be read in their entire context
and in their grammatical and ordinary sense harmoniously with the scheme of the Act, the
object of the Act, and the intention of Parliament”: Rizzo & Rizzo Shoes Ltd. (Re),  1
S.C.R. 27 at para. 21, 1998 837.
48] Thus, to the extent that Rogers’ position is that s. 12(4) of the Act must be read
together with the rest of s. 12, and in a manner that is harmonious with the rest of the
legislation, I agree. However, doing so does not support Rogers’ position. In my view, s. 12(4)
confers a broad discretion not subject to mandamus.
49] Reading the whole of s. 12 in its ordinary sense does not support the conclusion that
may” in s. 12(4) imposes on BC Assessment either a mandatory obligation, or a discretion
that is qualified to the extent that mandamus is available.
50] Section 12(2)–(3) sets out circumstances when the assessor “must” assess property on
a supplementary roll. The legislature would have, again, used the word “must” in s. 12(4) if it
intended there to be a mandatory duty to correct errors and omissions other than those
captured by s.12(2)–(3).
51] This view is buttressed by looking at the statute as a whole.
52] Sections 10(1), 10(3), and 34 oblige the assessor to recommend changes to a Review
Panel for errors and omissions. However, s. 10(2) provides that the assessor “may” amend an
individual entry before March 16 of the year following completion of the annual assessment to
correct an error or omission, if an owner or complainant consents.
53] There are numerous other examples where the Act imposes a duty on an assessor by
the use of “must” in the relevant section, including ss. 2; 3(1), (3)–(6); 10(1) and (3); 19(2), (5),
7)–(8), (10) and (13); 21(1); 23(2) and (3.1); 24(2) and 24(3); 25(5); 41(1); and 42(1); this list
is not exhaustive. Significantly, the legislation imposes a mandatory obligation for a
supplementary roll in relation to Crown land if certain circumstances exist: s. 26(5).
54] The prevalence of mandatory duties in the Act signified by “must” suggests that the
legislature did not intend “may” in s. 12(4) to impose an obligatory duty.
55] It is also important to note that s. 12 does not create a “right” for anyone to have a
supplementary roll issued. Instead, it requires an assessor to make a supplementary roll in one
of two situations: (i) property was liable to assessment for the current year, but not assessed in
the current roll (s. 12(2)(a)); or, (ii) property was assessed for less than the amount for which
it was liable (s. 12(2)(b)). Section 12(3) also mandates the assessor provide a supplementary
roll for similar corrections in the previous year’s roll, but only in defined circumstances as set
out in s. 12(3)(c)–(f).
56] Consistent with s. 12(2)–(3), s. 12(4) similarly does not speak of a person being able to
apply for or ask for a supplementary roll; rather, it states only that an assessor may, at any