Again, I do not know the guy. I know his name, and the town he lives in, but I'm not posting personal information on this forum. Several people I work with do know him. Both photographs were posted on my friends facebook pages. And again, the story that was told to the newspaper does not add up to what could have caused such a severe gun failure.
Personally, I can't see this happening with anything but smokeless powder. But I don't know the whole story, so I'm not claiming that's what happened. I've heard of, but not seen, stories of three 777 pellets blowing up inlines that were not rated for such heavy loads, so I won't discount the possibility that he just overloaded the gun, and didn't fully seat a bullet. But again, that's not what the newspaper story said.
I'm not going to be an armchair quarterback and make expert statements on something I don't know the whole story about.
A bit non-related, but many years ago I read an article in Guns and Ammo about attempting to blow up a T/C Hawken by overloading it. They mounted the barrel to a remote firing system and gradually began overloading it. After each shot they would measure the barrel for swelling. My memory is fuzzy, but I'm thinking they got up to 300 grains of BP and 7 Maxi-Balls with no damage. They finally put a double charge under a Maxi-Ball, then pushed another Maxi-Ball half way into the barrel. That destroyed the barrel.
Does anyone remember the MythBusters eipisode where they tried to recreate the "banana barrel" myth? They ended up welding a plug into the muzzle of a rifle, I wanna say it was a .303 British, but not sure, before they could even split the barrel. They never got a blowup like the picture I posted of the muzzle loader.