Earlier quoted context omitted.
Also, we know now that it's illegal to remove customers after boarding, unless they do something illegal. Saying no isn't illegal.
It is a federal crime to not follow crewmember instructions, so...
Bumping a well behaving passenger in preference of a "more important" one doesn't really fall into either category.
Considering the passenger in this story has already consulted legal counsil, I'm thinking the lawyer agrees that he did nothing wrong.