I give OP the benefit of the doubt that they only apply their logic to defendable, human vs. human interactions, but even then - You can get PTSD no matter what you do.

Successfully preventing someone from taking your wallet can cause PTSD, surviving an IED blast without injuries can cause it, etc.

You can get PTSD "just" from witnessing a stranger being robbed.

And of course getting PTSD doesn't mean that someone is weak-minded or whatever.