I always presumed that at least some of the bikers were guilty, but the gross misconduct by the judges, cops, and prosecutors overshadows the whole mess.
Maybe a few started shooting at each other first. Or maybe it was provoked by an undercover agent as some of the bikers claim. In any case you don’t fire into a large crowd because a couple of people in the crowd shoot at each other. I suspect that the reason they aren’t filing charges is that the videos would be so damning to the police they can’t let the defense have access to them. Better for the cops to drop the whole thing.