I actually had this happen while in TN hunting wild boars. I was behind a tree with a group of pigs about 15-20 yards away. My buddy was standing over my shoulder video taping it. When I shot all the pigs ran off except for the one I hit. He kinda jumped from the string noise. I knew it was a perfect behind the shoulder shot. As he walked off he was scratching at the entrance wound with his hind leg. He walked off about 30 yards and got wobbly legged and plop!