I've made the point in an number of recent posts (e.g. HERE and HERE) that radio and television interviews seldom generate anything but bad news for politicians - but only hit the headlines if the interviewee slips up and says something that the rest of the media thinks worth reporting.
One of the most spectacular cases of such a gaffe came when David Dimbleby was interviewing Mrs Thatcher two or three nights before polling day in the 1987 general election - in which she referred to people who "just drool and drivel they care".
Dimbleby immediately picked up on her choice of words, in response to which she apologised (twice) whilst revising what she had said.
The drool and drivel sequence was quite widely replayed and reported elsewhere in the media but, luckily for her, it happened so close to polling day that there wasn't time for a big story to brew up and it had little or no impact on the eventual result.