Then your union sucks.
If this guy is union, and if said union isnt as garbage as yours, this guy would have a good chance of keeping his job.
All he would have to do is cite long hours, being asked to stay later than scheduled, too short of a turn around time, etc.
Source: Not only am I a current union member, but when I was with a different union at a different job, one of our guys showed up to work on his day off, drunk as a skunk, and decided to bypass the guard shack and drive straight through the parking lot chain link fence.
He was initially fired. But thanks to the union, he went through arbitration and got his job back. Didnt even have to pay for damages to the property because the union picked up the bill for that, too.