Man thats tough but it does happen. If you hunt long enough and are lucky enough to get a lot of shots then it is bound to happen eventually. On the 2nd day of season for me I shot a doe at 25yds I felt it was a good shot but I only found 1 drop of blood and it was about 45yds from the shot. I knew the way she ran so I walked another 30 yds or so on the path and came out in a gasline looked up nothing looked down and there she was. The shot was a little high so all the bleeding was to the inside period. She had ran maybe 80yds total.