While it sucks that you got into trouble for trying to do the right thing, a lot of people here will agree the best course of action is to just stay out of other people's problems.
Basically I got a broken nose and broken knuckle and the guy got a fractured eye socket so it wasn't "Just a scuffle" according to the Arresting Officer, the cop said he had to arrest me because I was bleeding everywhere. The other guy was resisting arrest the whole time and I surrendered right away.... I just think the justice system has turned into an assembly line, few officers or judicial employees can give a **** anymore.