Feldman J.A. (with whom Rosenberg J.A. and Swinton J. agreed) commented as follows:
[59] Again, applying the Dunsmuir test for reasonableness, the delegate engaged in a full and logical analysis of the issue. He understood the problem, he addressed the arguments made, he referred to case law of this court and of the Supreme Court of Canada and he arrived at a conclusion. The Divisional Court found that his conclusion was beyond his jurisdiction and also that it was unreasonable: not within “a range of possible acceptable outcomes.”So, if you are before the Ontario Court of Appeal defending an administrative decision-maker, make sure you demonstrate that there was (1) a full and logical analysis, (2) that the decision-maker understood the problem, (3) that the decision-maker addressed the arguments made, (4) that the decision-maker referred to relevant case law, and (5) that the decision fell within the range of possible acceptable outcomes. (It would be a bit much to have 'arriving at a conclusion' as a separate requirement...)
Number (5) is present in Dunsmuir, but the others seem like a refinement of Dunsmuir's requirement of justification, transparency and intelligibility in the decision-making process.
I am not sure how helpful such procedural 'markers' are in determining whether a decision is actually reasonable or not, but I suppose they could function as useful guidelines to decision-makers, counsel and judges.