First of al those are extreme examples, for every failure like that there are over a hundred instant kills. Hell People have been hit by almost every type of caliber and lived. Lots much more powerful than a shotgun. I know of a girl who fell from an airplane 10,000 ft in the air and lived. The human body can be an amazing thing. Even though the guy lived through it he was down and out and most likely would have died without medical attention.

All I know is this...

If I hit them (anyone) once center mass with my 3 1/2" 0000 buck load or my 3" brenneke slug load, they won't get up...

From Squirrel to Elephant, the Shotgun is your gun.