I doubt that there's just about anyone who is surprised that politicians and civil servants collude to cover up crimes committed by their own, up to and including murder. Our expectations of the probity of the State are so low that we have ceased to regard such things as remarkable. Can you name any exposure of misdeeds by a member of the political class in recent years that was a result of being dobbed by his own? All those I can think of have been exposed by the press and the public.
Nor, I think, should we be too hung-up on some old cases from the 1980s. The real scandal is that it is undoubtedly still going on; that there will be MPs, peers and senior civil servants known to each other to be paedophiles, rapists. thieves, fraudsters and sundry crims, and that it's still the job of the Home Secretary and the Met Commissioner to quietly and in an unattributable manner sweep the muck under the carpet, lose the files and have juniors tell complainants "He's a powerful man; all you'll do is make trouble for yourself".
Twas ever thus.