While it sounds like the police were called way too early for this, if the airline wants the pax off, the police should be escorting if the passenger refuses to leave as it is a trespassing issue at that point. Putting the onus on the police to determine if the airline should be allowed to remove the passenger also puts the liability on the police if someone who is sweet to the police causes an issue inflight that leads to a much worse emergency. If they don't feel the airline had a valid reason, write it up in the report and make sure the passenger gets a copy.

Also, regardless of how much the flight crew appeared to have screwed this up, I'd be gobsmacked if any of them were not Canadian taxpayers