It seems to be a case of criminality for one country and not for another. Very strange state of affairs.
I agree. As mentioned, mentoring a licensed pilot toward their float rating does not require that the mentor be an "instructor". I have presented a PPL to an authorized person, for a float rating, which was issued based upon my recommendation that my training and his skills met the requirements.
So the events described in Canada were legal in Canada. It seems they somehow had a big miss in safety, (presumably not the result of a deliberate intent to injure) but that is not a crime. The fact that the Swiss could find a crime in there is worrisome. Perhaps that event contained all the elements for a crime in Switzerland, But it did not occur there, other than perhaps the arrangements.
I would be fascinated to learn the detailed reasoning of how an event completely legal which occurred in Canada can be prosecuted as a crime elsewhere.