I got a few new holes in my thumb today, thanks to a wayward pneumatic stapler. The unit double-fired, so the second staple ricocheted off the first and shot straight through my finger. There was an exit wound... however, I recoiled from the pain so abruptly, that instead of pushing my thumb down and away from the end of the staple, I just pulled it towards me, forcing the the staple to come out sideways, tearing my flesh around the side of my thumb between the entry and exit wounds. I don't think I hit any muscles or tendons... just several layers of skin. It bled a lot.