Do you drop it, or make it your business anyway?

Returning to your car in an underground lot you see a Hispanic man later 20s run to a car and fumble with his keys. You hear “there he is!” and the man fumbling takes off again. He is quickly surrounded by 3 younger men, 2 marines in dressed olives and khakis, and a sailor in crackerjacks, a marine and the sailor seizes the man by his arms. There is shouting but you can’t hear what is said. There is no one else near and you have no camera phone, and you see no lot cameras. Then you hear the Hispanic man plead near the top of his voice “I was just kidding!” But the other marine punches him 4–7 time about the head and body when he slumps to the ground the marines and sailor leave yealling back “next time you better watch your f****** mouth f***ot!” You go to the guy and ask if he is OK and if you should call the cops, he says no cops, he just wants to go home, that he was leaving _______ (a popular bar & grill for straights and Gays) and just said the wrong things to the wrong people but that is wasn’t nothing. He has been drinking but don’t appear drunk so maybe he could drive. Do you drop it? If he doesn’t want your help can you force him to take it? Do you call the cops anyhow? Do you figure he don’t want the cops because he may not be legal? Do you figure he got punched because he was Hispanic or maybe because he was Gay?