Shot placement looks perfect. How was the exit? Where did the arrow exit? Great to see your persistence in the recovery.
Phil - I did not get a pass through, but I watched the arrow hit the off side shoulder. I was 22ft up and the deer was 18-20 yards (I don't know exact, I know he was green pin range), so shot angle shouldn't have had any issue. 10 yards into track, he broke arrow off (as you see in the first post) 1-2inches from fletching. When I found the deer, the entrance looked perfect, he must have had his offside leg back a smidge and the exit looked directly across from the entrance. However, I couldn't discern exactly where the exit was due to buzzards picking slightly at exit already, so it could have been 1-2 inches moved one direction or another.
I can say that it appeared the BH might have closed on itself, the hole in the front lung looked like it was close to the diameter of the arrow. It was to the point it, that I had a hard time really doing a full autopsy.
An absolute, unusual situation.