It sounds like the dad came out GREAT! The guy got off light on the possession charges, no doubt influenced by his heroic effort.
I don't know why y'all think it is so terrible that this guy got charged for possession of an illegal weapon. He was in violation of the law before the incident which brought it to the attention that he possessed an illegal weapon. It just happens to be the hero event that brought his illegal activity to the attention of law enforcement.
What if he had used a switchblade knife, brass knuckles, or a stolen car? He still would have been a hero and still in violation of the law.
The guy possessed a gun where he needed a permit he didn't have and so after defending his family, he now has the expense of all the legal hassles. Why the guy didn't bother to get a permit is beyond me. He probably figured there was little chance that anything would ever happen and so he didn't bother with the permit. That's just the way it goes.