BTW 3refs, I can't find a thing funny in your story.
I must just not get the joke. On the face if it this sounds like a terrible abuse of power by a camp commander who sunk to the level of the Nazis, but I'm sure there must be something funny in it, right. Maybe the funny faces of the German prisoners after the the troops had worked them over for a while; or how funny they might have looked trying to walk with a smashed kneecap or two?
Yeah, that must be the funny part.