Who was more a fault, Teasle or Rambo?
All of this probably wouldn't had started in the first place had Teasle just let Rambo (who was minding his own business) go on his way and not give him a hassle over being a Vietnam War veteran. Why should it be a big deal for Teasle concerning where Rambo could or couldn't go around town? It isn't like Rambo is a registered sex offender or a high profile past nuisance.
On the other end, Rambo wasn't being cooperative when he's in police custody. Of course, Teasle's fellow officers couldn't have known that he was suffering from a severe case of PTSD. But still, Rambo decided right then and there, that it wasn't worth the trouble to be formally arraigned and decided to start a fight.