This was not an instance of Mr Crouthers having to make a split second decision where no matter what he chose to do, someone was going to die. There was no break in. In fact according to the police report there was no evidence even of an attempted break in. The boy never entered Mr Crouthers' house. He wasn't even standing at the door when Mr Crouthers went outside to look for him. He was drunk and went to wrong house, that's it. The police had been called and were on the way, no one was trying to break in, and Mr Crouthers was safe inside his house armed with a shotgun. That's hardly life or death. This was not a chain of events set into motion by the drunk young man that led inevitably to his death, Mr Crouthers made decisions the whole way, and he's responsible for those decisions. He chose to grab a loaded gun, he chose to open his front door and go outside looking for an intruder, and when he found him he chose to shoot him.
Mr Crouthers and his lawyer are now claiming as part of his defense that he did not know the gun was loaded and he only wanted to scare the boy. Think about that for a minute. He says he took a gun that he thought was unloaded(ie, useless) and went outside looking for the intruder. Would you do that? Does that sound like he was in fear for his life? And I'm not even going to get into the part of responsible gun ownership that deals with knowing whether or not a weapon is loaded.
The court may well find him not criminally liable, but he's clearly responsible for what he did.