Well im my families experience not mine i have never gut shot a deer before but in there opinion you are gonna lose the blood trail eventually and when that happens the guts will have filled in the wound at that point from what i am told the deer has about another 2 to 3 hours of life it was good of him not to track it immediately has he probably would have ran all over the place to get it and then he would have to look for it as the blood trail would have stopped gut shot deer usually die a very slow painful death and for future reference i would advice your friend never to take a shot like that again.