Infallible opinions?

When I was in high school, I would sometimes ask friends to fill out music surveys I created.  I would ask them to grade various songs I'd heard, and I'd tally the results.  One friend, before filling out each survey, would tell me, supposedly jokingly, "And remember, I'm right."  His opinions about the songs, in other words, were supposedly the right ones and beyond dispute.  Naturally, he was being facetious.  Or, perhaps not...