Rule #1: The gun is always loaded. Rule #2: If in doubt, see rule number 1.
He missed a step. You don’t just drop the magazine and think it’s empty. You ALWAYS inspect the chamber, manually if possible. That should be practiced until it’s automatic, much like taking the thumb safety “off” (if so equipped) on the draw.
Also, when presenting a weapon to another person, you drop the magazine if equipped and lock the action open or open the cylinder (and remove the rounds) and leave it that way.