They say, Eckoh pay
Channel 4 pleads ignorance
Finding out exactly how much Channel 4 knew about the dubious practices going on at Eckoh concerning the running of the "You Say We Pay" quiz would be rather difficult, but it's likely that Channel 4 is being fairly honest on this matter since it surely would have been the case that Eckoh would have had more ammunition to somehow implicate Channel 4 as a "partner in crime".
Of course Channel 4 is still implicated in this affair but only on the lesser crime of "dereliction of duty", namely that it should have kept a closer eye on Eckoh as it operated the cash cow quiz instead of lazily sitting back and raking in the revenue, plus being a 'public service broadcaster' made Channel 4's dereliction of duty subjectively worse.