This is definitely not an expert opinion, but my untrained hunch is that the divergent answers did it. I remember trying out some internet sample questions on my DS when he was little out of curiosity, and he gave some unusual answers like your son (things like: “doesn’t have three vowels in the name” or “doesn’t have another possible name” or “is inanimate and made of things that were formerly animate”.)
Those answers were the reason I never bothered testing. He was going to answer whatever he pleased and bend the test to his will. Cheap answer, that. ☺️
