Can a decision maker in interpreting a statutory provision, in the context of reasonableness review, fail entirely to address all possible shades of meaning?

It can happen that an administrative decision maker, in interpreting a statutory provision, fails entirely to consider a pertinent aspect of its text, context or purpose. Where such an omission is a minor aspect of the interpretive context, it is not likely to undermine the decision as a whole. It is well established that decision makers are not required “to explicitly address all possible shades of meaning” of a given provision: Construction Labour Relations v. Driver Iron Inc., 2012 SCC 65, [2012] 3 S.C.R. 405, at para. 3. Just like judges, administrative decision makers may find it unnecessary to dwell on each and every signal of statutory intent in their reasons. In many cases, it may be necessary to touch upon only the most salient aspects of the text, context or purpose. If, however, it is clear that the administrative decision maker may well, had it considered a key element of a statutory provision’s text, context or purpose, have arrived at a different result, its failure to consider that element would be indefensible, and unreasonable in the circumstances. Like other aspects of reasonableness review, omissions are not stand-alone grounds for judicial intervention: the key question is whether the omitted aspect of the analysis causes the reviewing court to lose confidence in the outcome reached by the decision maker.