Just playing devil's advocate. Even wiping up the sauce is an alteration. Take it as a learning experience, and soldier on. We have all made mistakes like this. (I have messed up shops that can sometimes be fixed and sometimes cannot. Not saying it is frequent, but it happens) My initial reaction was similar. The truth is, the client makes the rules, and the MSP only has so much leeway. If the client cannot use the shop, the MSP cannot either. Perhaps you can get a re-do. It is natural to be upset about it, because no one wants to be wrong. It may take a few days to get there, but once you have taken a step back, you might be able to see their side. Hopefully you won't write them off for one rejected shop.