It is amazing how much "empty" space there is inside a deer's upper chest cavity. I had a similar shot, but slightly further back and at a steeper angle. I watched the deer run away with about 1/3 of the arrow sticking out. We searched for him later and found very little--not even the arrow. 2 weeks later, I was able to lure the same buck in with a grunt from about 70 yards. When he passed under my stand, I could see clearly that he was the same deer, now with only a slight limp to show for our previous encounter. When he stepped into the spot I had shot him 2 weeks prior, he bolted--almost as if jarred by the memory. I don't believe he picked up my scent, or my presence; I am convinced he had a "flashback" and ran off.