The interesting question appears to be whether an instruction from the aircraft crew not related to safety or other requirements in the CoC is legal if it involves a breach of contract?
I was once bumped off a flight from LAX to LHR after I had sat down in Business with a glass of champagne. Given $250 cash, a voucher for meal in a posh restaurant in LA, a First Class ticket on a redeye to New York and a First Class from JFK to LHR on the morning flight, free telephone calls, and got home 12 hours later than I would have done. Plus F class frequent flyer miles......
That was back in the mid 1990's though, on American.