Hard to tell. I once fainted at a job with a tiled floor and smashed my chin against a sharp corner on my way down, then my skull bounced against the floor. I woke up and felt like I had been beat with a brick and a chunk of my chin was missing. They always warn not to sleep after concussions since brain damage is no joke. It might have been a mistake on his part not to call 911. Might have also been a murder. Unfortunately it's one of those things we'll never have the answer to.