Sorry RooFlyer, I seem to have touched a nerve.

It is absolutely true that flights from Switzerland are subject to EU261 like any other flight from any EU country. On the other hand, Swiss courts are not bound by the interpretation nor precedents of EU courts. Exact same regulation, very different interpretation and decisions. Specifically, Swiss courts have held that mechanical issues are often not considered within the airline's control. See this post from One Mile at a Time:

How SWISS Avoids Paying Compensation For Mechanical Issues - One Mile at a Time

I am not saying that they would not get satisfaction through the Swiss court system if it came to that, however, it is not the sure thing that EU court precedents would enforce from an EU country. I am most certainly not a lawyer and have no idea if a precedent for crew scheduling issues has been set within the Swiss court system, so it might be pretty straightforward but it is not necessarily as straightforward as it would be in an EU country. Trying to prosecute this through the Swiss courts would seem to be considerably more of a problem than trying to deal with it through Canadian regulators and Canadian courts for a passenger from Calgary thus my suggestion that they try AC first, Canadian APPR second, and EU261 as a last resort