"oh gee, this world record class buck walked by but i didnt have a shot at his lungs or heart so i let him keep strolling down the path to go frolick happily with his friends." And dont say you wouldnt take that shot either.
I can say that I, for one, wouldn't take that shot. If the lungs and heart aren't available, I'd certainly take a neck shot, no problem. It the deer doesn't allow a neck shot, it's walking. No hind quarter shots for me. Let him live to see another day instead of blowing all of the meat out of his @ss. That's being a game hog.