Nick Robinson gets the runaround

This sort of thing is absolutely, definitely not to be encouraged. And yet the BBC's political editor Nick Robinson 's election update last night was ever so slightly enlivened, not only by the mystery chap suddenly appearing behind him, but the Keystone Kops way in which he appeared to be chased off. By a BBC producer perhaps? As Robinson was saying at exactly the time he was interrupted, "it's all about personal credibility".