When he asked for forgiveness it was not for an illegal invasion of a sovereign nation, but for a brief interruption to Sir Roderic Lyne, his principal foil on the Chilcot Inquiry. Another apology a couple of hours later was for the fact that the Iraq war had proven so divisive: "I'm sorry about that."
Those who switched on or logged in expecting to witness any single act of contrition from the Catholic convert were sorely disappointed.
After a slightly shaky start they were instead treated to a silky display of verbal dexterity; one in which the panellists asked questions which were then praised as being "good", sometimes "very good" and, on occasion, even "very, very good", at which point Mr Blair then began answering an entirely different question of his own devising.
Yet in the first few minutes a different outcome had appeared possible. After being smuggled in a side entrance as early as 7:30am, Mr Blair resembled a man whose nerves were stretched on a rack. His face was taut and his top lip solidly locked in place. Smart in a dark blue suit, crisp white shirt and red tie, the former PM listened as Sir John Chilcot, the inquiry chairman, told the audience that this was not a trial and yet when Mr Blair reached for bottle of water his hands had the visible tremble of a man condemned.
The last time Mr Blair had seemed so nervous was perhaps 16 years ago, before a debate among the candidates for the Labour leadership. Yet after a few minutes the confidence, eloquence and expansive hand gestures that had served him so long and well rolled slickly back into play.
Openness was illustrated by open palms, pertinent political points came with his hands rolled into fists but with the thumb and forefinger straight out and touching like the beak of a pecking bird. A few times he even put his hand on his heart. The thin wire-rimmed glasses were on for inspecting documents in a lever-arched binder or off and wielded in his right hand like a rapier slicing up erroneous ideas.
In just such a manner his inconsistencies slipped by unchallenged. When asked about the different attitude towards Saddam Hussein before and after 11 September, 2001, Mr Blair said: "It wasn't that objectively he had done more. It was that our perception of the risk had shifted." Yet in the foreword to the September 2002 dossier he had written of being "increasingly alarmed by the evidence from inside Iraq".
When he tried to brush off the recent interview with Fern Britton – in which he appeared to suggest he would have invaded Iraq even if he had known there were no weapons – as a junior mistake, commenting: "Even I with all my experience, it (the interview] could still indicate that I've got something to learn", there was an audible gasp in the room, with one spectator saying: "Don't think you can get away with that one." And yet he did, as Sir John Chilcot breezed on to the next subject.
Outside the protesters were now chanting "Tony Blair, where are you, we will throw our shoe at you", but inside he was now merrily batting away each question with growing aplomb. On the "45-minute claim" – which referred to battlefield munitions inside Iraq, but which many misunderstood to refer to weapons that could have been used internationally – he did offer his first concession. He said: "It would have been better to have corrected it."
On the issue of regime change, which was always the United States' stated objective, but which other witnesses from Tony Blair's government had insisted to the inquiry was illegitimate and illegal, the former prime minister insisted that "regime change" and "disarmament" were effectively the same thing.
Later, in the afternoon, when questioned about the failures of post-conflict planning, he said that of invading a country, "a lesson you learn is that whatever preparations you make this is always going to be tough". A point of such striking obviousness that you could imagine the spectators slapping their palms to their foreheads.
Yet the chairman then said of the conflict, which cost the taxpayer 7 billion, 179 British soldiers their lives and roughly 104,000 Iraqis their lives: "It has been an expensive lesson, but one it was necessary to learn."
At one point, Mr Blair said: "I think it's pretty obvious when you go back and look at (UN resolution] 1441 that a decent case can be made (for war]." He then waited for Sir Roderic to agree, but Sir Roderic said: "It's not for me to an express a view."
Mr Blair then tried the same trick a few minutes later with Sir Lawrence Freeman, when he said the Iraqis were better off now. Sir Lawrence corrected him by saying they were better today than in 2007, perhaps. "Or in 2003, or 02, or 01," Mr Blair implored, but, again, instead of agreeing Sir Lawrence said only that he had spoken to Iraqis and that remained to be seen.
An argument Mr Blair advanced a number of times was to imagine the threat Saddam Hussein would have projected in 2010 if left in place.
At the very end, after more than six hours of questioning, Mr Blair was asked if he had any regrets. He said: "Responsibility, but not a regret for removing Saddam Hussein. I think that he was a monster. I believe he threatened not just the region but the world."
Then he was gone, up and away, leaving only an empty chair, a half-finished bottle of water and, for some, even more unanswered questions than when he arrived.