In this case, the GA is also done...she is out of it and cares not what legal ramifications there are, she will never see the passenger again most likely. It will take some company 17 years of this to have enough ammo to fire the GA without a lawsuit for something.
Meanwhile the passenger who was their at the last minute, but apparently in time, got no flight and has to fight to get what is due to him for the actions of others.
I have always wanted to be able to scan my phone/BP at TSA and have the phone record the time or have the BP stamped by a timeclock type thing. Same for when you get to the gate, UC etc. For the someone watching me freaks, you could easily turn it off. That way United knows where you are and you know where you are, but they can't even track our baggage, so I am not surprised they do no better with people.