I saw the show and he said the head opened up. I don't think it did. There was a good size piece of rock gone when they showed it. IMHO he under estimated how high the rock was and tried to coverup by saying the head opened up. He was in a blind and the rocks were about chest high in front of him. The deer was in back of the rocks. His sight plain might have been o.k. but, the arrow is lower than that.

G