Since I don't know much about depression, being fired alone could be a trigger to a suicide on this person? Because shit happens to people everyday while they struggle to move forward. The situation clearly escalated there and the officer could have prevented it. But those two events (arrest and death) have no significant correlation to the officer himself.
It's like an employer firing someone, and getting the blame because the person commited suicide, right? I mean, he would be considered the trigger that put that person into that situation. The firing itself could be unreasonable just because one day you have a bad mood and happen to vent at the wrong time. And then you get fired, have a mortgage that you barely can pay, have depression... wouldn't that be quite the reason to take a definitve measure? Would you place the blame on the unreasonable boss because he fired that person?
I've seen situations where people are driven to suicide due to many factors making it impossible to look forward anything at all. But this, to me, isn't one of those cases where they put her into a situation that was unfixable and thus pushed her to commit suicide. In fact, we're being told she landed a dream job.