As is well-known, the Court held in Dunsmuir that there are two standards of review, reasonableness and correctness. Subsequently, it has made clear that there are certain categories of decision to which the two standards apply. Correctness for constitutional questions, resolution of jurisdictional overlaps, true questions of jurisdiction, and questions of general law of central importance to the legal system. Reasonableness for interpretations of a decision-maker's home statute, issues where law and fact are intertwined, and policy-making decisions.
In the copyright cases, the Court was reviewing decisions of the Copyright Board, the expert tribunal established under the Copyright Act to set tariffs for the use of copyrighted material. Within the post-Dunmsuir framework, the Act is clearly the home statute of the Copyright Board, and it should be presumptively entitled to deference (i.e. review on a reasonableness standard).
Instead, the Court introduced an exception to the framework. It explained, in Rogers Communications Inc. v. Society of Composers, Authors and Music Publishers of Canada, 2012 SCC 35 that the appropriate standard was correctness, because the Copyright Board shares jurisdiction with the Trial Division of the Federal Court. It is possible for an action to be brought to enforce a copyright in the Federal Court, which would require the Federal Court to determine the boundaries of the copyright in question. But part of the Copyright Board's role in setting tariffs is to make precisely the same determination.
Rothstein J. suggested that giving deference to the Copyright Board could lead to inconsistency. If the Federal Court were to answer a question of law in its determination of whether a copyright infringement had occurred, no deference would be owed and in any appeal, the standard of review would be correctness. But if deference were paid to the Copyright Board, the exact same question might be reviewable on a standard of reasonableness. From this Rothstein J. inferred that Parliament could not have intended deference to be paid to the Copyright Board's determinations of questions of law arising under the Copyright Act:
 It would be inconsistent for the court to review a legal question on judicial review of a decision of the Board on a deferential standard and decide exactly the same legal question de novo if it arose in an infringement action in the court at first instance. It would be equally inconsistent if on appeal from a judicial review, the appeal court were to approach a legal question decided by the Board on a deferential standard, but adopt a correctness standard on an appeal from a decision of a court at first instance on the same legal question.
In a strong set of concurring reasons, Abella J. disagreed with this logic. Deference has always been "based on the idea that multiple valid interpretations of a statutory provision were inevitable, and ought not to be disturbed unless the tribunal’s decision was not rationally supported" (at para. 69). Here, the Copyright Board was undoubtedly an expert body, to which decision-making authority had been delegated, and therefore deference was appropriate: Because of the unusual statutory scheme under which the Board and the court may each have to consider the same legal question at first instance, it must be inferred that the legislative intent was not to recognize superior expertise of the Board relative to the court with respect to such legal questions. This concurrent jurisdiction of the Board and the court at first instance in interpreting the Copyright Act rebuts the presumption of reasonableness review of the Board’s decisions on questions of law under its home statute. This is consistent with Dunsmuir, which directed that “[a] discrete and special administrative regime in which the decision maker has special expertise” was a “facto[r that] will lead to the conclusion that the decision maker should be given deference and a reasonableness test applied” (para. 55). Because of the jurisdiction at first instance that it shares with the courts, the Board cannot be said to operate in such a “discrete . . . administrative regime”. Therefore, I cannot agree with Abella J. that the fact that courts routinely carry out the same interpretive tasks as the board at first instance “does not detract from the Board’s particular familiarity and expertise with the provisions of the Copyright Act” (para. 11). In these circumstances, courts must be assumed to have the same familiarity and expertise with the statute as the board. Accordingly, I am of the opinion that in SOCAN v. CAIP, Binnie J. determined in a satisfactory manner that the standard of correctness should be the appropriate standard of review on questions of law arising on judicial review from the Copyright Board (Dunsmuir, at para. 62).
 The Board has highly specialized knowledge about the media technologies used to create and disseminate copyrighted works, such as the Internet, digital radio, satellite communications, as well as related economic issues: Copyright Board Canada, Performance Report for the period ending 31 March 2003 (online), at Section II: Departmental Context — Organization, Mandate and Strategic Outcomes. This specialized knowledge is precisely the kind of institutional expertise that Dunsmuir concluded was entitled to deference.I tend to agree with Abella J. Quite apart from the first-order question of whether one thinks deference is appropriate or not, there are four doctrinal problems with the majority's approach.
1. The inference as to legislative intent is dubious. If the legislature had intended for issues arising under the Copyright Act to be within the purview of the courts (which is really what a standard of correctness amounts to), it could have provided for an appeal. The failure to do so is a strong indicator that Parliament intended the Copyright Board, not the courts, to be the primary decision-maker in copyright matters, subject to deferential review.
2. The Court relied on the fact that shared jurisdiction meant the Copyright Board was no longer operating in a discrete and specialized administrative regime, language which it pulled from Dunsmuir (see para. 55). But in Dunsmuir, discreteness was only one factor which could lead to a finding that a reasonableness standard ought to be applied. To pluck one factor from one paragraph in a decision which aimed to simplify judicial review is a strange way of justifying a new "shared jurisdiction" exception.
3. The new exception will not simplify judicial review. It will complicate judicial review. Rothstein J. claimed that the exception will only apply to intellectual property regimes (at para. 19). Abella J. noted that this will cause a change in the trade-marks field (at para. 70). But beyond that, clever counsel will undoubtedly argue before provincial and federal courts that the existence of a private right of action negates the deference owed to interpretations of a home statute. After all, in an action, a provincial superior court or the Trial Division of the Federal Court will be called upon to answer any questions of law arising, potentially the same questions addressed by the tribunal in its regulatory functions. As with the Copyright Act, the Competition Act creates a private right of action which may overlap with the jurisdiction of the Competition Tribunal. Securities legislation in the provinces often does the same. Doubtless, counsel for the applicant in judicial review cases will closely parse the statute book in order to find "shared jurisdiction". Really creative counsel might even argue that public law duties which can ground actions against public bodies in negligence also create "shared jurisdiction". Working all of this out will be complicated.
4. The Court overlooked the possibility of using alternative methods to resolve any conflicting interpretations that do arise. The "paramountcy"-type analysis employed in British Columbia Telephone Co. v.Shaw Cable Systems (B.C.) Ltd.,  2 S.C.R. 739 is one possibility. But more generally, the Court could have trusted in the ability of the Federal Court and Copyright Board to work out any problems between themselves. To put it starkly, the Federal Court would need a very good reason to depart from a decision of the Copyright Board and vice versa.
Now, none of this is to suggest that the Court did not have good reasons to be concerned. Potential inconsistency is something worth guarding against. But given the need for the Court to formulate clear and coherent doctrine for application by lower courts, innovations should really be kept to an absolute minimum.