I don't know for sure, but both are likely enough to warrant an investigation. Again, one's guiltiness doesn't make the other one innocent. The only reason I don't insist on falling like a ton of brick on Tyler is that it seems obvious to me, and it looks like everyone already agrees about that part.

Moreover, I don't care much about what happens to that individual cop (as long as he's banned from ever carrying a weapon he's proved himself unfit for). The guy is dead, too late. What I care about is exemplarity: I want the next cop in a similar situation to feel like "if I pull the trigger, my career, freedom and reputation are probably over". That seems a proportionate amount of skin in the game, before voluntarily taking a citizen's life.