The very same thing happened to me and a friend this past muzzleloader season. I made a drive for him and jumped up a small 4pt. buck. He made a poor shot on the deer, knocked it down but it got back up and ran away. After looking at the faint blood trail, I decided that we had better wait a while before looking for the deer. We went to another section of the farm and he made a drive for me but nothing showed. After about 2 hours I returned to where he shot the buck and I put him on a stand out past where he shot the buck hoping that if it jumped up again he'd get it before it went onto some posted property. After about 1 hr. of tracking and back tracking, I jumped the buck up but it wasn't going toward his stand. I radioed him and told him I had located his buck but it was still alive. He responded" shoot it if you can" which I promptly did. When he got to where I was he asked "who's buck is it?" I said it's yours. He was my guest on this hunt and he was perfectly willing to give me the deer but I wouldn't have felt right about it. I killed one of my own before we got back to the truck and he was more excited about my kill than his. Good sportsmanship makes for memorable hunts.