The Marine was clearly shitfaced, guy should have just walked away. His girlfriend was a piece of shyte!
Do you think he could have though? It looks as if they were on the corner table and they repeatedly told him to go away and the dude kept grabbing the guy and at one point looked like he was trying to kiss him or something but the tatt'd guy got control of his hands. Looks to me like they were packing up things trying to avoid the situation but the drunk refused to back down no matter how many times the tatt dude tried to de-escalate.
So sure, he could have tried to go around him but then takes a risk of the guy hitting him from behind with a chair or bottle.
Some will say maybe give him a slight push so they could get buy but then risk the drunk falling or taking it as an aggressive move and attacking them again from behind.
It's only my opinion but if some dude is all over you physically, in your face in a threatening manner then get riled up and puffy chested when hearing your girl say lets go ..you need to make a quick decision cause he's feeling froggy and is getting ready to leap. This guy was out for a fight and wasn't going to let it go until he got was he wanted.
Lesson here is, learn to control yourself when drinking and don't act like some 21yr old kid who took a karate class when he was 15 and now thinks he's invincible and pick a fight with someone who can beat that ass.