One circumstance where the airlines reserve the right to take you off is if you're flying on an employee ticket - you agree to un-board if that's needed.

This led to a humorous (though perhaps apocryphal) story concerning a (male) employee named "Gay" (perhaps short for Gaylord). After he took the wrong seat, the counter agent came on and asked the passenger in the correct seat if he was Gay. The unsuspecting passenger made the obvious incorrect interpretation, and answered that indeed he was! "You'll have to get off, sir." At which point our hero said "No, I'm Gay; I'll get off" and another nearby passenger announced "I'm gay, too - they can't throw us all off!"

Back to Chauming's situation, or lack thereof, I agree that we need more information to comment...and his lack of same makes me suspect the airline did the right thing.