Sorry I was not clear. I agree with you, what Rudolph did was not a case of muscular memory. But there are other people in this thread who may disagree. For me, it was his excessively paranoia but still, his surprise it is a little weird. I thought TWG had made him shoot but I realized I was wrong because it would interfere with his free will. Still, conditions were created and probably He (They) guide the bullet, leading to an injury that gave her enough time for a goodbye without making his suffering too long.
Perhaps the surprise was because Rudolph knew he was pointing to another place and the bullet trajectory felt weird, as if in "Wanted".