Well, that stinks for the kid. I hit a 200lb plus 6 pt once from about 65-75 yds with a 308. Chunks of meat at the hit site. Hair everywhere. Deer ended up being about 60 yds away just hanging out when I got Down 30 min later. Too soon I know but I was too excited. He ran of course. Small blood pool where he stood for half an hour. Not a spot after that. He ran like fire to a cutover never to be seen again. Went back to see that my bullet had hit a small branch on a bush. Pretty sure I took a chunk of his brisket off.
This deer was shot with a 308 as well. You just reminded me of one detail I left out. The dad had found a small piece of meat when he tracked it. I think it was from the front shoulder or brisket…..or maybe even lower neck. It sounded a lot like your story. They thought the deer was smoked so they got down pretty quick to recover it and likely spooked him off. That's why the blood stopped....he was running.