A drunken man's transexual encounter ends with violence, is there someone to blame?

Was it too much booze that made this guy react the way he did or would he have done it anyhow under the same circumstances?

I was chatting with a guy I knew and he was reminiscing about his younger drinking days and how he and some friends went out to this bar which was known to be frequent by transsexuals. He and another buddy spots the 3rd wheel of their outing chatting up a transsexual (going from male to female) at the bar. They were familiar with the individual but their 3rd was clueless. He was short and small framed and had good work done as to not look masculine at all so I was told. Also he had what I was told a very natural set of aftermarket boobs. This 3rd guy spent most of the night buying the drinks sucking face, and feeling up the transsexual which he thought was a hot chic, to the entertainment of the other 2. He kept trying to cop a crotch feel but was blocked every time until near closing and they were both pretty hammered, I guess the transsexual’s defenses was weaken by too much booze and the 3rd got a good feel of 3rd base and found a man on it. The guy I knew and his buddy busted a gut laughing at the 3rd an outcome they suspected would happen eventually. This guy tricks the transsexual out back to the alley under the guise of allowing the transsexual to give him a BJ. He then pounces and pummels the poor tranny into a bloody mess. When the other 2 goes back in the alley and see what has happened to their 3rd wheel and see what has happened they hustle the 3rd guy away.

Do you believe the 2 that knew was partly to blame by allowing things to happen for their amusement they don’t think they were? Was the transsexual partly to blame because he did not reveal that fact before accepting all the free drinks as the story teller believes? Did the 3rd seriously over react because he was drunk or he would have gotten violent anyhow? Should they at least gotten aid to the transsexual before high tailing it out of there to keep the 3rd out of trouble the least they could have done? Is it the 3rd wheel’s fault for being too drunk to know who he was sucking face with and feeling up, which I believe? Was anyone at fault at all?