Clever response!

It reminds me of those tricky questions in the find-the-truth type puzzles where you don't know whether the person is a liar or a truth teller. The tricky question is, "If I were to ask you [whatever it is that you need to know] would you say yes?" If the person is a truth-teller they will say yes if the answer is true or no if it isn't, but for the liar, if the answer is true, they would lie and say no, but in answer to the question they would have to answer yes to "would you say yes?" so you would know that the answer was actually true. Double jeopardy.

As an aside, I watched a quiz-type show called Tipping Point yesterday where the question was (approximately, from memory) "what two-letter word comes before the word 'brainer' to mean a concept widely agreed upon?" and the the poor contestant buzzed in and then paused and said he couldn't think of the answer because he had "brain freeze". I thought it was funny. No brainer leads to brain freeze.