The media has decided that Sir John Scarlett's interview with BBC correspondent Gordon Corera represents a flat denial. The Independent shouts that there was "No collusion in torture, says M16 chief"; the Guardian "MI6 chief denies torture complicity". Even the Associated press goes with " MI6 not complicit in torture, says chief"
Only the BBC's website, though not its News Channel, quotes what Sir John actually said. You can listen to the interview here.
The relevant excerpt starts at 2:14 into the interview. Corera asks the question, and after a couple of seconds thought, out comes Scarlett's answer " No torture and there IS no complicity in the torture".
The use of the present tense IS is important here.
I could be wrong, but I don't think anyone has suggested that M16 has been involved in the actual torture of prisoners. They have not applied the thumbscrews, Even Binyam Mohamed is not suggesting that M16 tortured him. What Scarlett is denying is that at present there is no complicity in torture. He is not denying that M16 have not been complicit in the past.