I think the issue isn't actual threat, it's perceived threat. And, cops perceive a lot of things as threatening enough to endanger your life upon.
But we know this. How to fix it? I don't think better training is the answer. I don't think cops will allow cams to work. I think incentives need to change.
Here's a fix: give a 40% (or whatever) pay bump to any officer that chooses to work without his gun.
We'll probably start seeing exactly where guns are required vs where they are an emotional crutch.