before numnuts went all HIV mass murdering.
It's kinda hard to tie a rope around one's neck, at hanging height, while holding a shotgun. If he tied the knot first, he wouldn't have been able to reach down and pick up the shotgun, unless he had it carefully propped against his body.
More likely, someone "ordered" him to climb on the table and stick his head in the noose, at gunpoint, and then shot him.