I am thinking that you never penetrated the chest cavity.....angles never seem to be exactly what you think they are at the shot....but at any rate, in my opinion, the deer was at a slightly sharper angle than you thought or your arrow glanced along the ribs and lodged under the near shoulder. If you did indeed get penetration of the chest cavity, you hit the front of a lung...which means they go a looong way. I aided in the sucessful recovery operation of a doe that went very close to 1/2 mile after getting hit similarly too far forward.