The only common ground to those cases are americans in US consulates. So logical conclusion is it is case of self-shooting in the foot - Us spy equipment malfunctioning etc
A logical conclusion, not the logical conclusion.
I think this comment (https://news.ycombinator.com/item?id=17135012) does a better job of starting to enumerate the possible causes.
https://globalnews.ca/news/3956401/eight-canadians-sickened-...
If it was a country way less friendly to the US than Canada (or even less friendly, if you want to make the questionable argument that Canada is not friendly to the US), that would be a better indicator.
That said, asserting that it's not "beyond the realm of possibility" that this phenomena might affect US allies because of shared equipment is pure conjecture. Many things about this are not beyond the realm of possibility.
Going public is really the only response that makes strategic sense, irrespective of the causal factor.