Thanks val and mithawk, honestly I would prefer NOT to bring it up to the teacher because the last time I said something she did not react well (see my earlier posts about the categorization of the word stranger as something someone does).

My concern is that, although no grade was put on the test, he is a perfectionist and internalizes these grades as his own failure ("I'm bad at science"). We are working on this separately, but incidents like this don't help at all.

I think I have been avoiding undermining the teacher's authority by telling him that the questions are poorly written and that he is in fact correct. But I guess I am going to have to do that, though, in order for him to feel secure in his own abilities, which is ultimately more important.