Ahhh not really UNLESS Benn drew without any being assaulted in some way first. But if the ex-cop pepper sprayed him that is assault. Its all down to who touched who first.
True to a point. If Benn was getting in his face in a truly hostile manner, then the pepper spray was warranted. We don't know what happened. All we have is Benn's story, which is either true or a self-serving fabrication, and the police's story, which is either based upon witness testimony and/or video, or a fabrication.
It is far more likely that a jailed man will lie about his situation than an entire police department will, but if I were on a jury I would require evidence and testimony of the man's guilt before convicting, even though I think he's probably guilty.
In other words, distrusting the police would not be my default position, but they had better have more than just a guess about what happened. If they have no evidence or eyewitness testimony, Benn goes free.