Seems to me, if you hit him in the butt or hip or leg, you should have found some blood somewhere, if it was a significant hit. It's not like an internal organ shot, where the blood can pool inside. If you hit a majot artery in the leg or hip, it should bleed, I think. I would look hard for any blood, then sleep soundly if you don't find any. Oh, and I would check your release thoroughly. That could be dangerous.