Sounds sympathetic contraction. One hand squeezes suddenly (usually unexpectedly) and the other does so unconsciously.
Unless trigger finger discipline is hard wired in (and sometimes even when it is hardwired in) the principle of affordance means your finger will likely wind up on the trigger.
This is also why people are directed not to try and catch a dropped gun or to hold onto a gun if you trip or fall.
https://www.policeone.com/archive/ar...2h6XBiLr9Ie5j/
https://www.emerald.com/insight/cont...4683/full/html
An “affordance” refers to the possibility of an action on an object; Guns are designed to be shot. Therefore the optimal grip on a gun is designed for your finger to fall naturally on the trigger when you grip the gun. This is why trigger finger discipline requires conscious effort or training to a level of unconscious competence.
https://en.wikipedia.org/wiki/The_De...veryday_Things
Lucky > Good.