Yeah the analogies aren't useful. The actual laws about air travel are though. Airlines can legally bump you from a flight. There are laws about what kind of compensation you are due if this happens.
That said, the rule seems to be that once you've boarded, they need specific reasons (behavior, safety, etc.) to remove you from the flight. In this instance, it sounds as if the airline fucked up.
https://www.transportation.gov/individuals/aviation-consumer...
That said, the rule seems to be that once you've boarded, they need specific reasons (behavior, safety, etc.) to remove you from the flight. In this instance, it sounds as if the airline fucked up.