Those are extremely WRONG assumptions.
Farmers know the difference.
Veterinarians know the difference.
Scientific investigators know the difference.
Predators and flies etc. will descend quickly on a carcass which has been taken down by other means.
They WILL NOT TOUCH—OFTEN FOR YEARS—a carcass mutilated by the ‘others.’
We are ranchers and have been for 50 years. That is the way cows look that have died of natural causes in the pasture. Their rectums have been eaten out and the small critters go inside their bodies. The birds peck their eyes and mouths, the skin tightens as it dries and appears to have been sharply cut. Any farmer rancher or vet who goes on camera and says this is a mystery is just looking for his 15 minutes of fame.