The "deny boarding" rule should be applied at the gate, not after passengers have boarded. This man was already sitting in his assigned seat when the crew realized they had to accommodate essential staff. And the "deny boarding" is about oversales, as in overbooked. The flight was not overbooked, only fully booked. And, there's nothing in the fine print that says the airline can beat you up if you refuse to give up your seat. United has already said that their procedures were not followed, so that’s an easy win for his lawyer.
The "deny boarding" rule should be applied at the gate, not after passengers have boarded. This man was already sitting in his assigned seat when the crew realized they had to accommodate essential staff. And the "deny boarding" is about oversales, as in overbooked. The flight was not overbooked, only fully booked. And, there's nothing in the fine print that says the airline can beat you up if you refuse to give up your seat. United has already said that their procedures were not followed, so that’s an easy win for his lawyer.