I don't know many of these interviewers (I myself interview but I would never ask people to do these silly tests) but I spoken to one of them from Boston a while ago at a party and he said he just has this list of questions and they need to be answered correct; he himself would not even be able to recognise if the person was attacking the problem right or wrong but he says 'I want to see how you approach solving problems' as that is what he has been taught. So in my 1 point empirical research I would say you are being lied to.