Reading both Mansoor Ijaz's account of the exchange and Romney's version, I'd say I believe Ijaz - because Ijaz has a detail that Romney misses. That detail is that Ijaz interrupted and clarified his question. My guess is that Romney was - surprise! - trying to calculate what his audience wanted to hear. Now we have evidence that he has given a similar answer before. Soren notes:
A combination of hypocrisy and implausible repeated non-denials is good material for a feeding frenzy.