When the little guy introduced a firearm to an argument, I would have to say it was the big guy who was suddenly in reasonable fear of death or serious bodily harm.
Either way, when two hot-heads collide, Darwin is likely to win.
Yes, but the shooter was at his home, after commanding the trespasser to leave, and the dead guy was a trespasser. So, they weren't standing on the same legal ground at the point the gun was brought into the picture.