You're not ripping him off if you ask him to fix something that he broke. I would think he would be ripping you off if he didn't offer to fix it.
For example a year or so ago, a friend of mine rear ended me driving like an idiot and not paying attention while there was snow on the ground.
His car was fine, but he punched a nice hole in the back of my car. I immediately called the police and had a police report made for fear that insurance wouldn't cover it if I didn't. The damages ended up being less than my deductable, so I "made" him pay for the whole thing which ended up being around $400.
I guess, my point is that he made a mistake and he needs to take responsibility for it however minor the damages.
