Seeing the arrow, and rereading how you hit the deer, I have a feeling you didnt really get a "pass-thru." I believe you may have hit just the very top of the back, (somehow missing the spine) and just sliced meat on the deers back. The arrow, in this type of hit, would look as if it were a pass-thru. From your picture, obviously, that is a meat shot. Secondly, I would say that your blades got bent by hitting the ground or something of the sort. If they hit his backbone, he'd have dropped.

My guess is its a flesh wound and that deer will be just fine. That high of a hit could explain why a deer was over there blowing. All he knows is he was over there, and now hes in a bit of pain. So he may have been warning the rest of the deer around.