While giving evidence at the trial of Stephen Ward,
Rice-Davies made the quip for which she is most remembered. When the prosecuting counsel pointed out that Lord Astor denied having an affair or having even met her, she replied, "
Well, he would, wouldn't he?" (from Wikipedia).
Hence, "MRD applies" means "he would say that, wouldn't he". Usually used to devalue an
opinion by drawing attention to the other-than-impartial situation of the person voicing it.
I
think this is a
silly idea, myself, but then, I’m a
state regulator, so MRD applies.
John Quiggin on badanalysis.com