I had a flight ticketed by Air Canada but operated by United that was delayed 12 hours for mechanical reasons (i.e., their fault). United gives something like $600 dollars compensation for delayed flight under their contract of carriage, but Air Canada, like most Canadian airlines, has much less generous compensation.
The answers to this question about airline bankruptcy suggest that the ticketing airline's contract of carriage applies, i.e., Air Canada, and that I would be out of luck. However, it seems like things can't be this simple because United's rules certainly apply to things like overbooking and how passengers are compensated if they are kicked off a United-operated flight even when they were ticketed by another airline.
Can I hope to get compensation from United?