No excuse... but I imagine he was not trying to remove the nut so much as blow the thing to hell after screwing with it for so long

I know that I have had similar urges, and while I have avoided using a firearm I did break out the sawsall once and hack off a troublesome exhaust manifold that pushed me over the edge. Yeah, I showed it!

Still, no excuse for this Darwin Award runner up.
Charon