Abbott's radio silence

Anne McElvoy asked Diane Abbott a perfectly reasonable question as part of a piece on the Labour leadership contest on the Today programme today (you can hear it here). The question was:

You have a son in private education. You said that you are in tune with the Labour membership. A lot of that membership doesn't like or accept private education. Isn't that a bit of a clash?

Abbott's response was silence for about 15 seconds, at which point McElvoy moved on to the next question.

Now, unlike nearly every other Labour supporter, I'm not currently that interested in the Labour leadership contest or the candidates involved. It still has two months to run and I can't currently bring myself to gaze at my navel whilst the coalition government is doing what it's doing. At this point in time, I thus don't have preferences either way as to any of the candidates.

But for Abbott to refuse to answer that question - let alone engage in the issue it represents - seems to be both churlish and detrimental to her prospects.