I hate to agree with Skip Bayless, but he's making sense here yet again. NBA players and athletes, along with celebrities, are public figures, and the brighter the star power the more likely it will attract a ton of attention.
I believe this is the case. Copeland and other NBA players attracted attention. There could be a little bit of taunting that turned into a heated argument. With alcohol involved it could go very wrong, and it did.
No one is stopping these guys to have a good time, but they also have to realize that they can attract attention, so why not just have a private party with friends and close acquaintances? Have it on a rented place or something.
Also, Ted Mosby is right, nothing good happens past 2AM.