RE: Downed deer gets resurrected...
My guess is that you hit high. I've seen it happen several times when m/l hunters overestimate the distance/holdover and hit a deer high in the back. Not low enuff to break the back, but low enuff that the shock knocks the deer down stuns the animal. Usually, they are temporarily stunned by the blow, but gradually regain their senses. Then, they run forever. May even leave a pretty good blood trail.
I lost the first deer in the past 15 years last season because of a similar poor shot. Almost the same exact scenario.
I have also seen the results later when we put dogs on wounded deer to try to recover and eventually get them. Almost every time the deer is knocked down and then magically gets up and goes later, when we find them there is a very ugly, high back flesh wound.
The deer may survive, but you will probably never find it.
Hank