This suggests a wound inflicted by a starburst of rat shot pellets which were far enough from the muzzle of the weapon to have separated from one another by as much as 2.83 inches before striking the head. Who would, or could, shoot themselves in the temple like this? Notice that the "spread of shot" is assumed from the wound diameter not actually determined. If you could see the wound you could tell without difficulty whether this was "spread" or "blowback".
Lots of assumptions here and most cannot be defended.