So how did this 'jaundiced' remit work in practical terms - without involving corruption? What instruction would be given to the officers examining the evidence? ''Oh by the way if you come across anything that looks as if it might incriminate the McCanns and their friends - just ignore it''. ?
The whole idea is too daft for words imo - and I'm still waiting for someone to explain why the McCanns ARE so important that a conspiracy involving the UK government was considered to be so vital in the first place. Any ideas?
AIMHO
The practicalities are easy to understand if you understand hierarchies. Those at the top decide what needs to be done and how. A detective working on sightings, for example, wouldn't see any evidence involving the T9 except perhaps Jane Tanner's.
Unless a team were asked to analyse the evidence against the McCanns they wouldn't do it, so nothing of concern would be found.
The McCanns were not important, just persistent. They persistently promoted the abduction theory, their own innocence and the inadequacies of the PJ. It's quite possible that Cameron, May and the Met believed them and wanted to help.