A bad lawyer could get around that argument. It is a principle in law that there are certain rights that an individual cannot waive, even if they want to. I would hate to be in Continental's position to have to defend that pilot error was the cause and because the passenger bought a ticket that said Continental would not be responsible for pilot error and therefore they had no liability. Or in Tropic's case that because the pilot did not kill anyone they have no responsibility for acting illegally.
Just some more thinking on a Saturday morning.