Why police looks for fire alarms when they catch a criminal?
I had smoke detectors in an apartment building I once owned, and we discovered that a cockroach running through the smoke alarm could set it off. Could have been caused by insects, but it does seem strange two of them went off at the same time.
IGNORE it. If you checked at the City's website and it says paid, just accept that. They will usually just cancel the ticket because your vehicle is not from Ontario, so it could show up on-line as paid. Toronto does this with thousands of out-of-Province tickets every year. Even if you did not pay and nothing else was done the most that would occur is you MIGHT get a letter in the mail, but no other action will be taken to collect any money from you.. The Province of Ontario has agreements to exchange information with several US States for moving violations like speeding, red lights, etc., which directly concern your driving licence, but parking tickets have nothing to do with that and there is nothing done about parking tickets.