Same type of scenario as your really. Was bowhunting one day when I had two does walk past me on a nearby trail. I drew a bead on the last one just behind the shoulder and let fly. What I didn't see was a small branch between me and the deer and right in line with where I was shooting. The arrow deflected and hit her in the leg, cutting the femorhal (spelling?) artery. Blood sprayed everywhere and she died less than 30 yards from where she was hit.