When I first began training kids to shoot, I faced an incident where one of the students had a question about the operation of the firearm he was working with, and turned to me with the gun in his hand, his finger on the trigger, the muzzle pointing at my kneecap, a round in the chamber. I was able to grab the muzzle and turn the gun away and up so no one else was muzzled, taking the chance that the move wouldn't cause the lad to squeeze the trigger on me before the muzzle cleared me. Once clear, I told him to let go of the firearm and step off the firing line, in a not too subtle voice. I unloaded the gun and then took the kid back to behind the staging area where I lit into him some about not listening to what he'd been told and not taking the training seriously. He was shaken, but I didn't get into him so much that he broke down. I wanted to make sure that if he ever picked up a gun again, he was a lot more careful about it. For that session, he was done.

Sometimes you have to be assertive about the correction in order to leave a suitable impression. It is the nature of who we are. Taking the kid off the firing line for the day gives him some time to reflect more objectively about what happened and let the discipline sink in more, so that the next time he goes shooting, he is more prepared mentally and more aware and focused on what he is doing, and also more understanding of some of the consequences of screwing up.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)