I'm not going to let my 13 year old girl have access to any firearms myself (personal choice) due to a 13 year old girl I knew having committed suicide when I was a teen. Sometimes emotions at that age are too much.
Regardless I'm happy this turned out well. I'm sure that family (and that young man) is going to have some mental struggles to overcome, but it's infinitely better than the alternative...
Guilt is the primary occupational hazard of parenthood. No matter what
you do or don't do, if it turns out badly you will second guess yourself for the rest of your life.
No answers from here, by the way. I'm just admiring the size & scope of the problem. There's no "right" answer on things like this -- just varying degrees of what you can live with if it goes badly.