That's a decent example, but I don't see why one-star vs five-star would make any difference. It's also depends if continuing to sink time/money into the meal (by having desert, say) would make you feel more sick or not. Unless you feel like vomiting, maybe you want to stay for that tasty desert anyways!

You'd only be committing the "sunken cost" mistake if you continued with the meal without having some good forwards-looking (social, perhaps) reason to do so.