But there isn't an armed individual in the house. You've just been told that there might be. Don't you see how you've fallen into the epistemological error here of not only assuming the truth of a claim without further evidence, but also shifting all your attention tot he possibility of someone being armed.

That sounds very hand-wavey and you might say well it's a lot different in the real world, but I've been in a bunch of high-danger real-world situations. Survival is about more than having great reflexes, it's also about having a cool head and knowing when not to act.

And look, while it's legitimate to have some fears/stress, rage monsters are absolutely a problem in policing. Cops are just as likely, or more, to take steroids or be assholes as people in the general population. Let's not forget that nobody is forced to be a cop. If you want to help people and like excitement you could always be an EMT or a firefighter.

Your version of deescalating the situation is to remove the suspect as quickly as possible

See, that's not de-escalation, it's catharsis through crisis - literally the exact opposite of de-escalation. By abdicating your own decision-making power you've ended up arguing for counterfactuals. I realize that you're attempting to model the thought process of police in high pressure situations, but counterfactuals + weapons = deadly errors. The thought process is, however, something we could change.