It only seems that the hair and fingernails "grow" because the corpse looses fluids and thus shrinks. Hair and nails stay the same length, so they seem to be longer compared to the shrunken body.
The "knees" on the elefents forelegs are the equivalent of our wrist joint, thus they are no knees.
Shocking how much bullshit is composed in such fact lists, especially since I can only confirm or falsify a few of them, so I guess there are even more fallacies.