Sure, it was a journalistic gaffe but it was a genuine mistake, for which they have apologised. Rather than defend itself, the BBC is its own harshest (and its own actual, when you consider the motivations of those attacking it) critic.
For anyone wondering why they should still pay their licence fee at this point, the true answer has nothing to do with tradition and people in glasses wanting to watch highbrow jolly-hockeysticks programming. The true answer is that we need an organisation of such integrity to stop, well, evil. Imagine a Britain without BBC journalism