did you consider a shot that was back and high as you know the most fat on a deer is on the rump and also the brisket area is normally fatty as well but this would have been white hair the rump is my guess. I hit one in the neck about four or five inches forward i had to lean out and shoot around the tree i was in and i tracked him for about three days before the conceding i had lost him but there is no toughfer animal then a whitetail deer for survival. I have seen some that still had a broadhead in cased in grizzle a friend shot one with a aluminum arrow snapped of on both sides that was lodged in the deers neck and never touched a thing to kill it he said he could hear him trying to clear his throat so he shot him he said that the wound holes were nearly healed over and you couldn't see the arrow he hit it with his knife while gutting it