Last year, on the anniversary of Bloody Sunday, the Government published an analysis of the Widgery Report in which it stated that one of its key findings was "grotesque and unjust" and contrary to the "credible evidence" available at the time.
Yesterday, new forensic material assembled at the behest of Lord Saville, the successor to Lord Widgery, attested to the strength of the Government's assertion.
Lord Widgery's suggestion that some of the 14 people killed and the 13 wounded in Derry 27 years ago might have handled or been in the vicinity of guns or bombs was effectively repudiated by forensic experts appointed by Lord Saville's team.
Conclusion 10 of the Widgery Report of 1972 states: "None of the deceased or wounded is proved to have been shot whilst handling a firearm or bomb. Some are wholly acquitted of complicity in such action; but there is a strong suspicion that some others had been firing weapons or handling bombs in the course of the afternoon and that yet others had been closely supporting them."
It was this paragraph that allowed elements of the British establishment to persist with its claim, expressed directly or through a telling nod and wink, that what happened on Bloody Sunday was justified. It was also the paragraph that caused most offence to the wounded and the families of the dead.
The element of suspicion against the victims is pervasive throughout the Widgery Report. In his carefully-crafted document Lord Widgery created an impression of guilt while speaking of the absence of proof of guilt.
Lord Widgery chose to believe the evidence of the soldiers responsible for the killings. This may be understandable. Before beginning his inquiry he was reminded by the then Tory prime minister, Ted Heath, that the British army was "in Northern Ireland fighting not only a military war but a propaganda war".
But what was an exercise in damage limitation has for the past 27 years been gradually and incrementally discredited. There was a radical acceleration of that process yesterday when solicitors for the families released the new material given to them by the Saville inquiry.
Crucial to the Widgery Report, effectively exonerating the British army, was evidence given by former Northern Ireland Office forensic expert Dr John Martin of lead traces on the bodies. But three British scientists who re-examined Dr Martin's evidence - Dr John Lloyd, Dr R.T. Shepherd and Mr Kevin O'Callaghan - judged his findings to be suspect. Dr Martin had found that many of the victims were exposed to lead particles discharged by firearms.
Dr Lloyd, in his report, found that Dr Martin's evidence was "worthless". Dr Martin himself, in a statement to the Saville inquiry, questioned some of his own findings of 27 years ago.
Dr Lloyd was critical of the forensic methodology of 1972 and suggested that what he and his two scientific colleagues had discovered should have been found at the time of the Widgery Inquiry.
Dr Lloyd said it was "profoundly disturbing" that a single particle of lead on a hand swab should have been considered as significant evidence that a person had been handling a firearm or been in the vicinity of a discharging firearm.
The scientists complained that the possibility of cross-contamination was not taken into account. For example, some of the victims were taken away in an army personnel carrier which was almost certain to contain lead traces that could have been transferred to them. Moreover, the lead traces found on the victims could have come, according to the experts, from a multitude of sources such as the victims' workplaces, from petrol emissions, lead in plumbing, metal sheeting, paintwork, bottle tops, fishing tackle, etc.
Eyewitness accounts of Bloody Sunday spoke of some of the victims being shot while they lay on the ground, while pleading for mercy, or while running away. They told of James Wray being shot dead almost casually as he lay wounded in the Glenfada Park area.
Lord Widgery came to no such conclusion, although he went as far as to say that the firing of the soldiers in Glenfada, where four people were killed, "bordered on the reckless".
The new forensic evidence points to something worse than reckless. It states that it was "most likely" that Mr Wray was shot as he lay on the ground. There is also evidence to suggest that some soldiers may have doctored their bullets so that they would fragment on impact, causing maximum injury. Lawyers for the victims said this was evidence of the soldiers using dumdum bullets, which are contrary to the Geneva Convention.
The Government, in January last year, apparently based on its own forensic evidence, said Conclusion 10 was "wholly unwarranted, unsustained by the evidence then or now and an unjustified calumny against the victims".
It added: "The victims suffered the double injustice of being unlawfully killed and having their reputations sullied for the purpose of exculpating the actions of those responsible for the deaths."
What emerged yesterday has gone a considerable distance to correcting that wrong. What still has to be established is - as at least one member of the Parachute Regiment in Derry on Bloody Sunday has alleged - whether the soldiers were acting under specific military and/or political orders on January 30th, 1972.