What is this guys problem?

Alcohol makes people do stupid things which they normally would not do were they sober. It is very difficult to tell how drunk someone is on video and only in very rare situations is it abundantly clear that a person on video is drunk or not drunk.So I do not know how you could state that they were not so drunk. Plus it appears that your main gripe is that the guy in the video hit her back and apparently knocked her out. Since I did not see the video in question ,I am not sure how you knew and concluded that they were friends,that the fight was play fighting, or that she was allegedly being gang d. I would have to see the video and then come back to find out what your real question is. I also suggest that you rewrite your story and ask a question that is clear and then re-post it if you want.