It is clear that a new form of defence is emerging for those eminent figures who find themselves having to justify their actions to judges, MPs and the media.
It’s very simple. Just four words – “I did not know”.
From Rupert Murdoch to Harry Redknapp, and now Bob Diamond, it seems to be working very well. They have all used it as an effective barrier against further questioning.
In fact it works much better than refusing to answer the question and, however incredulous the interrogators may be, there is little they can do. MPs and others will bluster, as Labour’s John Mann did yesterday, that “you are either complicit in what’s going on, grossly negligent or grossly incompetent”.
But those words will simply bounce off a thick skin. Or leave a Diamond unscratched.