My first instinct would be to leave, try to flag down a police car while dialing 911. However, the woman was blocking the door, and her boyfriend was also either in the doorway or near the doorway while hitting the victim. That leaves very few options.
As to my possibly interfering in the altercation, I am 60 with arthritis and a few other health problems. I am in no way ready or able to physically intervene; I'll keep my man card anyway. It's easy to imagine holding your ring to the green lantern and getting super powers, but the reality is that those guys see two people beating up on one victim (yes she tries to stop the beater, but she started the physical confrontation as well) and have no idea how to intervene or what the risks are (nobody has mentioned the possibility that the BG may have more friends outside) so they stay frozen. In a stress situation, you revert to your training; these guys likely had none.
I also find myself disturbed at the reactions of the news anchors. They are laughing. If they had been there in person, I'm pretty sure that they would have needed to change their underwear.
Moron Lave (send a Congressman through the car wash)