Gotcha. Like I said, it really seems like the problem is a police training system that essentially encourages "Feel vaguely threatened? Better shoot first."
The fact that almost none of them are ever prosecuted for gunning people down in the more extreme situations can't be helping either. There is no fear of repercussions beyond administrative punishment or being fired, at which case many officers can just find work with a new department.
But that's the point - there are a number of issues at play here, and nothing is getting solved because tough on crime politicians and police unions refuse to truly address these problems, and actively obstruct attempts at true, meaningful reform.