Yesterday, the Canadian general said he never knew where he was, other than somewhere on the island of Ireland.
Almost two years' ago, in October 2003, General de Chastelain arrived at Hillsborough Castle to brief the press on the IRA's third act of decommissioning.
He was tired and dishevelled and there was mud on his boots. Quickly it became clear then that more than just the location had been blacked out from view. Tragically, the general, when pressed, was unable to quantify the size of the arsenal, to give any idea how much Semtex, AK47s, and other weaponry had been destroyed. Within minutes the great prize of a rejuvenated peace process disintegrated.
But yesterday was unmistakably different.
This time, the report was powerfully persuasive. Persuasive enough for both governments, for most of the media, for the vast majority of people who watched it live. Persuasive enough for everybody except for unionists.
This time, de Chastelain was able to say that what was destroyed was "consistent" with the estimates he received separately from British and Irish security forces in September 2004. This time, it wasn't an intermediate step. He was able to say based on the inventory, on what he saw, on what the IRA told them that the whole shooting gallery was gone. All the guns were banjaxed, to employ Martin McGuinness's description.
Sure, he accepted, there was an element of trust. But the strong supporting statement from the two clergymen was compelling, especially that of former president of the Methodist Church in Ireland, the Rev Harold Good, a hugely respected figure.
"The experience of seeing this with our own eyes ," "provided us with evidence so clear and of its nature so incontrovertible that, it demonstrated to us ... that beyond any shadow of doubt, the arms of the IRA have now been decommissioned," said Rev Good.
Gen de Chastelain, and his colleague Andrew Sens, accepted there was an element of trust that could not be avoided. "We have no way of knowing for certain that the IRA has not retained arms. But it is our understanding and belief they were sincere when they said that," said Gen de Chastelain.
The IRA following Ian Paisley's 'sackcloth and ashes' speech last December was never going to agree to photographs. Its refusal to supply an inventory also came about because by doing so would be tantamount to a humiliation, admitting to defeat.
As such, the act was imperfect. But the unwavering belief of the IICD members supported by the two clergymen that the totality of the IRA arsenal was destroyed: that was the message that was borne home, and not the imperfections.
Though fettered from giving exact figures, the vastness of the arsenal was left in no doubt. Brigadier Tauno Nieminen spoke of hundreds of thousands of rounds of ammunition. De Chastelain listed the gamut of weaponry ammunition, rifles, machine guns, mortars, surface-to-air missiles, handguns and explosives. He said every type listed in the defence magazine, Jane's, was included.
Later, details of the Government's own estimate seeped out: 650 Kalashnikov rifles; 40 machine guns; a number of high- powered sniper rifles; up to six SAM 7 surface-to-air missiles; over three tonnes of Semtex; vast quantities of assorted ammunition and an "indeterminate" number of handguns.
And for once, you could be persuaded Gerry Adams meant every single word during the SF press conference in their most simple, most direct, and, yes, most sincere terms.
"Some unionist might fear that this is a tactical manoeuvre or an attempt to trap them. It is not. Some unionists have expressed fears about a Plan B. There is no Plan B.
"The IRA's decision to formally end the campaign and (decommission) are genuine attempts to revive the peace process by conclusively resolving the concerns of unionists."
And it was clear too that both governments after so many last-minute failures were going to row behind the IICD, and by extension, republicans. The moment had arrived. The IRA had given up the game. It had now given up the arms.
Tony Blair expressed no doubt. Taoiseach Bertie Ahern put it in almost visionary terms a momentous day, a landmark decision.
And inevitably he turned to the next horizon now that a sea had been crossed: the responsibilities of unionists to restore devolution; that of loyalist paramilitaries to follow the IRA's lead and stop their criminal and murderous activities.
"I urge (unionists) not to underestimate the importance of today's developments," said Ahern.
Yesterday, they were deaf to the pleadings, giving an indication of the difficulties that lie ahead.
Ian Paisley's rejection of the process and denouncement of all who were involved in it were true to his form. The two witnesses were approved by the IRA, he claimed, and therefore in no way could be independent.
There is another inventory. It is made up of intangible things. Death. Tragedy. Violence. Bloodshed. Atrocity. Heartbreak. Injustice. Anger. Rage.
This is it. It's all over.