I think that's a better way of phrasing the question. However, I think my real issue is just that it's difficult to rummage through your mental database of past bugs in the space of a few seconds. (Realistically, it's awkward to pause for more than a few seconds before answering a question in a face-to-face interview.)

What would be the downside to giving the candidate a heads-up that you're going to ask this question?