Appeals - Standard of Review - Dunsmuir
Gilmor v. Nottawasaga Valley Conservation Authority (Ont CA, 2017)
In this case the Court of Appeal nicely summarizes important appeal 'standard of review' principles to be drawn from the leading Dunsmuir v New Brunswick (SCC, 2008) case:
 Following the decision of the Supreme Court in Dunsmuir v. New Brunswick, 2008 SCC 9 (CanLII),  1 S.C.R. 190, it is well established that there are only two standards of review – correctness and reasonableness – and a standard of review analysis is not always required in order to determine which standard applies. In a series of cases, the court has established that the reasonableness standard applies presumptively when a tribunal is interpreting its home statute or statutes that are closely related to its function: Edmonton (City) v Edmonton East (Capilano) Shopping Centres Ltd., 2016 SCC 47 (CanLII),  2 S.C.R. 293, at para. 22; Mouvement laïque québécois v. Saguenay (City), 2015 SCC 16 (CanLII),  2 S.C.R. 3, at para. 46; Canadian National Railway Co. v. Canada (Attorney General), 2014 SCC 40 (CanLII),  2 S.C.R. 135, at para. 55; and McLean v. British Columbia (Securities Commission), 2013 SCC 67 (CanLII),  3 S.C.R. 895, at para. 21. Correctness review is confined to a narrow range of cases in which the presumption of reasonableness review is rebutted.
 Dunsmuir limits correctness review to four categories of questions: constitutional questions; jurisdictional questions; questions of general law both of central importance to the legal system as a whole and outside the adjudicator’s specialized area of expertise; and questions concerning the jurisdictional lines between two or more competing specialized tribunals. When a tribunal is required to decide one of these questions, the presumption of reasonableness review is rebutted: Dunsmuir, at paras. 58-61.
 As the Supreme Court explained in Dunsmuir, at para. 47, reasonableness is a deferential standard of review that is appropriate because of the nature of the questions that come before administrative tribunals:
[C]ertain questions that come before administrative tribunals do not lend themselves to one specific, particular result. Instead, they may give rise to a number of possible, reasonable conclusions. Tribunals have a margin of appreciation within the range of acceptable and rational solutions. A court conducting a review for reasonableness inquires into the qualities that make a decision reasonable, referring both to the process of articulating the reasons and to outcomes. In judicial review, reasonableness is concerned mostly with the existence of justification, transparency and intelligibility within the decision-making process. But it is also concerned with whether the decision falls within a range of possible, acceptable outcomes which are defensible in respect of the facts and law.