It wasn’t a straight-up self-defense shooting, but apparently legal nevertheless. I don’t think there was a need to go get the rifle when he could have called the authorities. Also, since the other guy was so big, he took a huge risk in that the gun could have been taken from him since he was in really close proximity to his opponent. Not really wise behavior on both men’s parts in the matter. Really sad overall.
Prosecutors in my state are hesitant to try and build a case on the "you should've called 911.." excuse. Primarily because of slow or no police response. When I moved to my current location, I was told directly by the sheriff's department: "Do you have a gun? We can't really protect you this far out in the county."