I blacked out once, and all my friends knew I had blacked out. Either your buddies don't know you as well as they should, or you're just a really dumb drunk. See what I did there, I made a statement rife with assumptions on your situation and I don't even know you!
The accomplices distracted her friend, just so the dudes could take advantage of her. If what you're doing to the person is so bad, that her friend wouldn't let you do it, that's a pretty clear indicator you shouldn't be doing it in the first place. She did the right thing, and brought a person she trusted to take care of her. By your logic, the sexual assault of a child is perfectly fine, as long as they were willing. Statutory rape shouldn't be illegal then? The child is not capable of making the decision, same as a drunk / drugged person.
The simplest analogy is this: Stealing. Is it right to steal something from someone, because they are too drunk to know you are stealing from them? If I ask my really drunk friend if I can take the 600$ out of his wallet, that's stealing, because I know damn well he is incapable of making that decision coherently.