This is not the first case of this happening. I actually rechecked the Intl to US MCT and was amazed, 85 minutes?? If US pre clearance is that backed up the filter it to recent flights to reduce backlog.

The problem is, without access to internal systems I don't see how you could prove the flight was overbooked; and I don't see AC providing this. It does make me wonder if there is a correlation between AC doing this and the connecting flight being a little heavy. If that's the case, it's at best a shady practice - but to prove or get anything for it?

Hang on, I assumed YYZ. Forgot Toronto isn't the centre of he universe, if this was another entry port those times are far close to 70 mins. If AC rebooked you despite being under the MCT you have a lot better case. It may not make a difference without taking legal action mind.