Originally Posted by exwannabe

I have no idea how this has been established.

If you are on somebody's property, and they insist you leave, you have to leave (there are of course some exceptions, such as living there). And there are specific laws for planes saying as such. When the police tell you to leave, you are certainly committing a crime by staying.

That UA might have violated their own COC is an issue one can debate. But that is a separate issue.

In general, I hate this phrase, but in this case it is perfect - Two wrongs do not make a right.