Looks to clean for a large caliber 20, 12g shotgun. Burn damage is also limited for a scattergun.
IMHO scenario, sitting on a couch, like the photos taken with pistol in hand, holding pistol toward a crossed leg. Picture indicates left foot, for a right handed shooter, they cross the weak leg over the dominant. Hence shot own self in foot with .45.
Had pistol on lap, left leg crossed over right, and BANG. with the .45.
Watched too many episodes of Quincy M.D. , and stayed at a Holiday Inn Express.

He needs some dressing for the exposed bone, and a broad spectrum antibiotic mui pronto. Than get a podiatrist, with some recs for shoes.
He'll be rather "gimpy" for a while.