That's not the law. When someone "asks" you to leave a place you have a legal right to be, and you refuse their request, you do not automatically become guilty of trespassing or fair game for violence. Lots of confusion in this thread between a civil request and a lawful order.
When someone asks you to leave their property, that means you no longer have a legal right to be there. The correct thing to do is leave and resolve your dispute with the airline in court.
I think you should in fact be allowed to physically throw someone out of your house/business that refuses to leave, without having to wait for the police. Avoiding this is easy, just get up and go.
