I don’t think its wrong guy in wrong job. I think its training. They are so hyped up that everyone is the enemy and out to kill them they react accordingly.
I see it a bit different. Personality cannot be overcome with training. The least capable personality types are attracted to today's realities in law enforcement. Those with the needed personality would not take the job today.
Many employers have this issue. Those of us hiring a congresscritter this fall understand this.