These (sometimes) automatic and perfect movements, like the body starting to do mudras or asanas you didn't know it knew I would say is common on psychedelics. You see this a lot at psy trance dancefloors

My personal interpretation is that you get a download of perfect yogic positions, maybe to fix something in your body-mind-soul or just to provide an optimal flow or dissipate of all the energy bombarding you on a good dose.
I don't think this "control" of your body would be usable for much else but dance or yoga and I think the fear/fury you experienced is unrelated to the movements.
From what I know psychedelic ninja powered violence is unheard of so relax, be willing to accept whatever is shown without attaching to it and enjoy what you body and mind learns.