That is really wild you got him on film. Hope you get another shot. That buck will be fine.

My buddy made this same shot last year on a buck, but hit forward toward the shoulder of where you hit that buck by about a foot or so, which by all means should have put the arrow in the lung area. Same deal - very little blood that dried up quick. I saw the buck alive and well a week later and saw him several times during season. I didn't take him because it was a small buck for my liking and he appeard to be very healthy.

You look at any anatomy chart of a deer and there is no mythical "hollow zone" or "void", but after seeing it in real life and seeing your experience, I don't know how to explain it.

How high up the tree were you and how far was the shot?