There isn't much info on it anywhere but from what I have read the likelyhood of a femoral artery self-sealing isn't likely.
Why don't you try to get us some details from your brother regarding the injuries he dealt with?
We get these types of claims often - on Youtube, forums, facebook, etc. and I have never seen anyone actually provide validation for these claims. there are always people running around with "I saw it happen, i have friend, a brother, etc." the vast majority of these cases people are BSing. don't take it personal that we are in doubt.