Last Sunday the Ulster edition of the People reported an allegation that Seán Maguire, the convicted IRA attempted murderer and current editor of the always entertaining North Belfast News, was a British army agent. Maguire strenuously denies the claim.
The allegation was made by "Kevin Fulton", a disgruntled former informer seeking compensation and relates to Mr Maguire's supposed presence during the 1990 abduction of Sandy Lynch (definitely an informer) by Freddie "Stakeknife" (possibly an informer) at the safe house where Danny Morrison (definitely not an informer) was subsequently arrested.
This opens up the intriguing possibility that three leading republicans spent a cosy weekend's interrogation together unaware that everyone present was working for the intelligence services, proving that no matter how Irish your cause you can still be British enough to enjoy a French farce. Tout le monde, perhaps?
Within 24 hours of the Maguire story breaking, Sinn Féin wheeled out the big guns. Gerry Adams demanded that the British government start "taking responsibility for those agents actively involved in spreading disinformation and causing confusion" while the party's vice-president Pat Doherty declared that "these allegations are the work of British spin doctors aimed at damaging the republican constituency and undermining the peace process", adding: "These allegations come from the same people who killed Pat Finucane."
But it is confusing that Mr Doherty should draw this particular parallel. Sinn Féin has worked tirelessly to expose the state's relationship with Billy Stobie, Pat Finucane's loyalist killer, claiming repeatedly that the peace process can have no meaning if it does not deliver justice in this and similar cases.
However those reporting identical links between republicans and the British are accused by Sinn Féin of falling for "dirty tricks" and branded "enemies of the peace process", even though in Stakeknife's case his British handlers may have turned a blind eye to upwards of 40 murders.
It seems that one man's collusion is another man's informing, a double standard which reveals both Sinn Féin's arrogant sense of exclusive peace process ownership and its quasi-religious need to defend the purity of the movement. Fortunately this isn't doing Northern Ireland any harm at all because the truth is that such scandals are good for the peace process. They may even be vital to it.
Pat Finucane and Stakeknife provide the perfect examples.
For 14 years Sinn Féin managed only to use Pat Finucane's murder as a sectarian wedge, first irritating unionists with Finucane's ludicrous post-mortem promotion to "human rights lawyer", then regularly antagonising them with the Pat Finucane Centre's angry propaganda.
In such a climate there was no prospect of unionists believing Sinn Féin's allegations of collusion. The publication of the Stevens report earlier this year, confirming that Finucane had been murdered by a loyalist informer and that his murder could have been prevented, resulted in an orgy of republican gloating which has obscured the report's effect on the unionist community. Unionists were genuinely shocked by the Stevens report.
Of course there had always been an understanding that the big boys occasionally had to break the rules, but the delusions of that excuse were a world away from the calculating immorality and squalid incompetence the report laid bare.
Unionists snapped out of their denial with an almost audible click, as politicians mumbled their regrets and former RUC officers expressed their shame. Even the DUP was reduced to calling for similar inquiries into IRA murders - a previously unthinkable admission of equivalence.
Sinn Féin, the party that would supposedly unite us all, should think long and hard about why this re-evaluation happened in spite of its behaviour rather than because of it. The Stakeknife affair provides a fitting republican counterpart, thanks partly to the alleged informer's high rank within the IRA but mostly to his pivotal role in the abduction of Sandy Lynch, which has become a set-piece example of the IRA's viciousness and vulnerability.
Like the Stevens report, the Stakeknife saga has also provoked a re-evaluation of attitudes on the ground. Initial attempts to deny the allegations in the west Belfast press were ridiculed by the wider republican community, which is increasingly prepared to treat Sinn Féin with the contempt a normal political party deserves.
What really makes these revelations a positive force is that they already seem like history - the incidents they relate to happened over a decade ago - and as the awkward historical facts emerge cynicism is replacing obdurate self-righteousness.
In normal societies cynicism is bad for politics, but Northern Ireland is not a normal political society. Cynicism here undermines not "the republican constituency" or the peace process - it undermines only the naïve absolutism which allowed both constituencies to live through the dirty war believing that only the other side ever got its hands dirty. That may not be good new for Sinn Féin, but it's certainly good news for the peace process.
Newton Emerson is a columnist for the People and the Irish News and editor of the website PortadownNews.com. He says he may be described as a unionist for the sake of convenience.