Same with the man who killed 40 people with a shovel with a fatal wound and survived
This makes no sense. If he survived, it couldn't have been a fatal wound. Just sayin'....
That proving that his story is inconceivable.
No, it's not inconceivable. You clearly consider it unlikely, but that does not make it impossible. It just means that you ain't buying it. And being skeptical doesn't mean (at least in my neck of the woods) that you get to call somebody else a liar - it only means that you are skeptical.
It shows in the link that a #6 bird will make a 6inch cavity in the body at 10 feet
Maybe I'm missing something, because that link is showing buckshot and slug tests and not birdshot. Having said that, I have no doubt that #6 birdshot will make a six inch cavity in a bucket of jello at contact distance. I'll keep that in mind if I'm ever being attacked by my kid's dessert or a giant amoeba.
Truth be told, #6 birdshot does a pretty good job of penetrating 3"-4" into the bodies of small upland game birds with rib cages so lighly constructed that you can dang near crush them in your hand. It's a little light for rabbit or squirrel unless ranges are pretty short, it's OK for headshots/neck shots on turkey, but it's way too light for game as large as a duck or similar waterfowl due to its inability to give adequate penetration even at close range.
That's a clue that it's probably not suited for critters that are an order of magnitude larger than a duck (unless they resemble a bowl of jello).
If I'm being attacked by a human or any critter bigger than a pheasant, then I'll likely choose to use a shotshell load that has been demonstrated in real life to actually penetrate the ribcage and other intermediate barriers to get to the jello inside of said attacker.
YMMV.