Now I don't agree with a 4 year old (at least any that act like mine) going deer hunting, but I think the earlier you start out with gun safety the better. I have a buddy that never was properly taught firearms because he didn't grow up with them. a few years back we went rabbit hunting. one ran out of the bushes and ran right past my legs, my buddy shot it in the rear end. I asked him why he didn't shoot it in the head, he said if he did that he would of shot me in the leg. He didn't realize that if it was that close he shouldn't of taken the shot because basic gun safety didn't click.
That same hunting trip he was standing on top of an old cattle shelter and another buddy was below him. This same unsafe friend says to our other buddy, "Duck!" Our stupid buddy says back, "Duck, I thought we were hunting rabbit." After he realized what he was telling him to do, our unsafe friend shoots over him!
Now my unsafe buddy is one hell of a good shot, he just doesn't know proper safety because he didn't grow up with someone to teach him.
Now in the military I shot over and around other soldiers and had others do the same. But it sure as hell wasn't with shotguns and we were trained a lot better and did it in a controlled manner, knowing there were buildings, hills, or enough space that it was an acceptable risk. Hunting, it is never an acceptable risk to shoot near someone.
I think kids should learn firearm safety and no law enforcement should view that as a bad thing.