At the Federal Court of Appeal Evans J.A. explained the problem (2012 FCA 92 at para. 34):
The interpretation of the Privacy Act is thus not within the scope of the Board’s expertise, and the presumption of judicial deference applicable to the Board’s interpretation of its enabling statute, or one closely connected to it, does not apply here.And he justified a deferential approach by noting that the issue was not one of "general application" of the Privacy Act and turned on findings of fact made in the labour relations context in which the Board is undoubtedly expert:
 To be precise, the Board had to make findings of fact about the CRA’s purposes in collecting the home contact information and about the use that PIPSC proposed to make of it. In addition, it had to define the scope of the duties imposed by the PSLRA (the Board’s “home statute”) on PIPSC as the bargaining agent of all members of the AFS bargaining unit, including Ms Bernard. On findings of fact and the interpretation of the PSLRA, the Board is entitled to deference.
In addition, the Privacy Commissioner had prepared an opinion for the employer on whether the Board's order would be a consistent use, an opinion that was put before the Board. Moreover, whether PIPSC’s proposed use of the information and the CRA’s purpose in obtaining it are “consistent” is a question of mixed fact and law that does not involve any readily extricable question of more general application that would elevate it to one of statutory interpretation. That the question in dispute does not involve the interpretation of the Privacy Act weakens the case for reviewing the decision for correctness, especially since the Board was applying a provision of that Act to a labour relations context, its undisputed area of expertise. On the basis of all these considerations, the decision of the Board in this case should be reviewed on a standard of reasonableness.
But even though the issue was teed up perfectly for it, the Supreme Court skipped over it almost entirely, saying only:
Thus no principled basis whatever was advanced for deferring to the Board's decision, even though it involved interpreting the Privacy Act. This is very disappointing (though in line with the minimalistic approach the Court has recently taken to doctrinal questions about the standard of review) especially given that this sort of issue was recently addressed by the Quebec Court of Appeal in Courses automobiles Mont-Tremblant inc. c. Iredale, 2013 QCCA 1348 (discussed here) and of course by Evans J.A. in the Federal Court of Appeal. In our view, the Board made a reasonable determination in identifying the union’s proposed use as being consistent with the purpose of contacting employees about terms and conditions of employment and in concluding that the union needed this home contact information to carry out its representational obligations “quickly and effectively”: para. 167.
In the absence of a statement of principle it is difficult to know if anything of general application can be taken from the Court's decision in Bernard. In recent times the Court has consistently reviewed decisions for reasonableness and has eschewed the interventionist correctness standard. But without a principled basis for deference offered from on high, reviewing courts around the country are more likely to succumb to the temptation to meddle in regulatory domains.