“Why was his finger on the trigger? They don’t teach safety? “
“Keep your booger finger OFF the bang-stick”.
It was more likely the little finger on his weak hand since the gun is held upside down when reholstering.
All of our weak hand draw, aiming, mag change, recharging, and reholstering out of a duty holster is done with dummy rounds. The scenario is that your dominate hand has been rendered useless. I can't imagine doing this with a loaded weapon except in a real gunfight because it is just too dangerous. The muzzle of the gun is pointed every which way when you turn it in your hand both drawing and then reholstering it. As for all of you safety experts and master gun fighters on here, try practicing this as if your life depends upon it like the deputy was.