Stepping up behind her, then taking a swat at the girls face tells it all for me.
Lets look at this sequentially.
Her and her female friend were doing something. They could have been waiting in line, loitering, they could have said something snarky at him as they walked over there, they could be being difficult with whoevers behind the desk, you dont know.
So he comes over and verbally expresses something. Is it irritation? Egotism? Anger? You dont know.
So they become just as confrontational as he is, and he, who looks intoxicated to me, very lamely slaps at her with something. Now she leaves with her friend.
So then her and her friend come back with who i read somewhere is her boyfriend and his pals. Watch the video, and you tell me that she and her friend are outside wondering whats about to happen. Is that what it looks like to you, or does it look like them going over to watch their handiwork? Run the scenarios in your head. They walk out of the store, and a few random guys walk in, so they both stop, go back, and watch through the windows? Or, they go out of the store, get their boyfriend, and come back to watch the beatdown. Which seems more likely to you, based on whats in the video?
So then, for the crime of meekly slapping at her for unknown reasons, him and his friend are sucker punched, beaten to hell and back, and left hospitalized.
Thats okay with you then, even with the sheer lack of information we have here to fill in the blanks?