this is kinda confusing...

you shot directly straight down on him?? found the arrow and its got 4" of blood and fat on it and the rest is clean??

you couldnt see where on its body the arrow was sticking out of???

walking funny and wagging its tail tells me it could have been a gutshot...but straight down...i dont know...obviously missed the spine...i just cant see an arrow being stopped by bone making a deer walk funny and wag its tail..usually when bone is hit hard that deer isnt going to stop or walk slowly, but will blow outta there hard and fast and not slow up for a little ways atleast...

only thing you can do is get out there and look...wait till the frost burns off and start where you left off...a high shot isnt going to leave much blood on the ground unfortunently...gather some buddies and search long n hard for the body after you lost the trail and hit all likely areas in the direction it was heading...