If they had been more polite and asked us to pay for the dish we ate, I for one would have agreed. After all, we had not noticed it was something we had not ordered. (Because 2 people ticked off dishes, each thought the other had ordered it.) But after the first loud accusations by the staff, my friend's reaction was perfectly normal. He responded in defense that it was their mistake for having placed it on our table in the first place. We thought that would be all.
I have to admit, as a local, he did react differently, trying to get me to just forgetabout it. So I'm just being an annoying self-righteous expat, am I?