I’ve had hot brass fly in a few unexpected places over the years. Did a few odd gyrations even.
I would assume the father is right handed and the usual reaction is to use the right hand to go for the hot brass - which takes the finger off the trigger.
A lefty would do the same in reverse.
I feel for the kid and the rest of the family. The Dad? Not a bit.
This jerk violated all safety rules. You make the gun safe and put the gun down. Then you deal with hot brass.
I’ve had hot brass stick to a couple of body parts - including my cheek. I have always set my weapon down on the bench, muzzle downrange (ok, very quickly) before addressing the brass issue. It just takes discipline. The guy screwed up, badly.