I don't feel any sympathy for the Father. Guns don't just go off.
This was extreme negligence. Not following the 4 rules of gun safety has some very serious consequences. Which was a lesson learned in the worst possible of ways. The school of hard knocks doesn't always hurt the person learning the lesson.
I'm sorry the child was the one who paid the price, and I am sorry for the pain the rest of his family has to deal with.