Personally, I think your wife is wrong on this one. You ARE letting him try again, just at a later time. You were right on by saying that this skill can kill you. Just like bike riding, roller blading, etc, where you wear a helmet, wrist guards, and so on. Or driving a car, wearing a seat belt. Thing is, you're most likely not making your kid wear a vest and kevlar helmet, right? Your safety precautions were right on, IMHO.

"If he can't make a mistake there..." Um, he DID make a mistake. And paid the penalty. He needs to make these mistakes, and be reprimanded, at the range, NOT while hunting with you. Does your wife have a logical argument here, becuase I'm not seeing it. What "mistakes" is he allowed to make that are OK here?

Interesting compromise you worked out. That being said, if your son doesn't know why he screwed up, you need to teach him that. Additionally, now would be a good time to address how to properly bring a dysfunctional weapon to your attention, as well as keeping his finger off the trigger.