What do you mean "causing violence?" It sounds like you're suggesting Hitler's moving of his arm somehow caused violence. Can you explain how that could possibly be true under your model of "arm movements don't matter"?

As far as I know, Hitler himself never struck anyone with an outstretched hand. Certainly that's not the crime he's accused of. I don't think you can actually prove that Hitler's arm movements had any causal relationship to the Holocaust, to be honest. So presumably he's in the clear, and there's no reason a normal person would've cared about Hitler's arm movements in the 30s and 40s, correct?

As far as I know, Hitler himself just said words. Same with Pol Pot, Hirohito, Mao, Stalin, and Lenin. How could you possibly attribute violence to any of that under your model of "I'm so smart I can't see causation or intent?"