“Despite the media’s best efforts to create a narrative, Dao was not an innocent doctor assaulted for trying to get to his patients.”
It is not relevant, legally. United should not have been trying to remove the passenger involuntarily in the first place; they were not on legal grounds to do so, by their own terms of service. Why the passenger did not want to deplane, voluntarily or involuntarily is irrelevant. His right to not agree to it was all the reason he needed.
You may be right (or not). But, either way, removing someone from a plane due to a mistaken policy is a minor issue, in the grand scheme of things. Give United a small fine. Let the public exact its revenge in the form of poor sales.