RE: Your opinion: whose deer is it?
I've had this happen once in the past and it was in agreement that the shot that was "fatal" was the one who took the deer. I guess it depends on the circumstances though. A buddy of ours shot a buck in the shoulder and the arrow was merely hanging from the skin. It came to my dad and I and my dad dbl lunged him and we found him the next day. At first our buddy tried to claim that it was his deer, but had my dad not placed the shot he did, the deer would have just had a really sore shoulder.
After reading the scenario though, I'd say its the 2nd hunters deer. Like I said, every situation would be different.