Protesting too much about collusion.
This would of course be the same MI6 that passed on information to the CIA regarding Bisher al-Rawi and Jamil el-Banna which resulted in their arrest in Gambia and subsequent rendition to Guantanamo Bay, and indeed the same MI6 which along with MI5 interviewed Binyam Mohamed while he was being detained in Pakistan, where we now know he was being tortured. The Intelligence and Security Committee noted even in their whitewash report into rendition that MI6 had likely given information to the Americans which was subsequently used in his mistreatment whilst in Morocco. We've since learned that "Witness B", an MI5 officer, also visited Morocco on a couple of occasions while Mohamed was being held there, even further heightening suspicions of direct collusion in his torture.
Those two others who declined to appear before the JCHR were David Miliband and Alan Johnson, who also seem to prefer talking to the media than having to face the chore of sitting before a committee with something approaching independence. Their article in the Sunday Telegraph, responding to the report's claims was one of those wonderful pieces of writing which condemns everything, states the obvious whilst not contradicting any of the specific allegations of collusion. It's the lady protesting too much: no one said, as they do, that the security and intelligence services operate without control and oversight; indeed, it's been quite clear that ministers have known from the very beginning just what the intelligence services have been getting up to, they've just denied and denied and denied it until finally forced to admit to specific allegations, like that two men were rendered through Diego Garcia despite previously repeatedly denying it. They've in fact just admitted that they are personally accountable for what MI5 and MI6 officers get up, so we'll know who should be prosecuted should collusion be revealed, and it's difficult to believe that at some point it won't be.