Do I lack a soul if i think this is just a series of unfortunate series of events?
I've had flights delayed massively, been bumped from a flight, and had other crazy long delays and events happen with air travel, it's part of the deal. Every time I fly I look at how busy a plane is and wonder about the chances of me getting bumped are. Everyone knows someone who's been bumped from a flight. It sucks, but it happens every day, probably hundreds of times all over the world every single day. And every day, people take their lumps and wait for the next plane. (and they take their $800 or whatever compensation).
Now we can debate the definition of 'boarding' until the cows come home, if he sues and win's they will just change the definition on the terms, because airlines need to have the ability to bump people occasionally. Even if they never over book and they are forced to keep 4, 5 or 6 or 10 free seats per plane, there will STILL be occasions due to non-normal situations that paying customers will have to give up their seats.
Why do UA staff have guaranteed seat priority? Well, probably because they need to be at the destination to staff another plane and keep the other planes (or essential part of the company) ticking over and providing a service. Staff not getting on a plane can cause all sorts of hassle and future delays that can snowball and spiral into massive delays for multiple flights, and eventually a bunch of customers are screwed over with delays and even cancellations - outrage You know, they kind of things people get outraged over already. And that's just one reason of many. But generally, staff missing at point x y and z for flight a b or c, it's not just a matter of calling in another bus driver or something.
So in that light, he is simply refusing to comply with 'the way things are' in the airline industry. This is a situation where there is no good solution. Lets remember what happens when you disobey flight crew in general in the air. The plane is immediately grounded and you are dragged of the plane if you even stall for a second when the cops arrive. We read such articles all the time.