I would be willing to bet that with the way that buck acted when it went into the field it was a better hit than you think. I hunt blacktail deer in western washington but I'm willing to bet that when hit most deer do the same thing. They hunch their backs tuck their tails and run. I must agree with MA Jay that you should have done a better job of sticking to the blood trail and that no matter where you've shot a deer if it beds down theirs gonna be blood. My dad shot a deer with his bow and she hunched up and ran about 75 yards and layed down we left her for an hour and came back and she had ran 25 more yards after laying in the spot we saw her stop in. It was raining hard but their was still blood in the bed so we knew she was hit and that she wouldn't be far, but we didn't give up when we couldn't find any blood anywhere else because of the rain. I've become quite good at tracking animals in the rain and I don't care how hard its raining there will always be blood in the bedding spot.