Alistair Campbell, Tony Blair's famously effective press secretary, was briefing a small huddle of journalists outside the talks building at Stormont on Monday afternoon when a reporter from one of the British TV stations strolled over, mobile phone to his ear.
"Tony seems to be in a bit of bother in east Belfast" he said. Campbell nodded and, apparently quite unperturbed, carried on talking about the British Prime Minister's commitment to the peace process. "He sees it as a historic moment of opportunity, one which will not come again in his lifetime."
The angry scenes and the accusations of treachery at the Connswater shopping centre in east Belfast were not part of the plan for celebrating Tony Blair's historic encounter with the Irish Question. At Stormont less than an hour earlier, the reaction of even the most cynical journalists to the prime minister's performance had been one of genuine admiration.
We have seen, most notably in the wake of Princess Diana's death, that Tony Blair has a rare gift for bringing a personal note to public occasions. Last Monday, standing on the steps outside Castle Buildings in the fitful sunshine, he made all the political points that we expected.
He had assured Sinn Fein that he wanted them to be inside the talks, but he also stressed that commitment to democratic methods and to the principle of consent was paramount. He had told Gerry Adams, and it must surely have struck a chord with the Sinn Fein delegation, that "we have a choice now, to remain the victims of our history or, finally, to make sense of it."
But what lifted the speech above the commonplace was the way Tony Blair talked about the victims of the decades of violence. He had visited Lurgan that day and met members of the RUC who had seen two of their comrades gunned down. He realised how difficult it was for them and many others to accept any talk of negotiation and compromise. "There was," he said, "a palpable sense of anger and despair", but that made it even more important to put the killing behind us.
It was a message which matched the mood of those who are fully involved in the talks. Several of them stressed afterwards that it was important, perhaps even historic, that the prime minister should commit himself so publicly to the peace project. Tony Blair has not had to take the same kind of political risks that both Gerry Adams and David Trimble have faced, but he will be damaged and his political judgment severely criticised if the terrible grip of history reasserts itself.
Already he has learnt, at first hand, that the fears which stand in the way of peace are much more intractable and deeply felt than anything he has experienced in his political career to date.
One local newspaper wondered whether Tony Blair had been deliberately "set up" by whoever decided to send him on a walkabout in east Belfast within an hour of his having shaken hands with Gerry Adams. If so, it may turn out to be no bad thing. As Deaglan de Breadun, this paper's Northern Editor, remarked, at the very least it provided "a valuable crash course for Mr Blair in the realities of Northern Ireland politics".
The prime minister's aides immediately rushed to limit the damage, saying that he was "unfazed" by a protest that was "clearly orchestrated". But Mr Blair is a shrewd and determined politician who does not lose sight of the main goal.
He wants these talks to work, and seems more focused than any of his predecessors on the historic prize of a settlement. He will demand to know whether the anger and suspicion which he experienced in east Belfast is widespread in the unionist community and, if so, how great a threat that could present to an eventual settlement.
I have written in this space before that the most urgent task facing both governments just now is to bring the Rev Ian Paisley and the people he represents into the process. It is only a short time since political strategists in this State were arguing that any talks that did not involve Sinn Fein would not be worth "a penny candle". It is true that Dr Paisley can no longer summon the bogy of the loyalist paramilitary groups to his political aid. Their representatives are now safely inside the talks (though this should not blind us to the serious tensions on the outside).
But the DUP still represents a sizeable proportion of the unionist community, including many of those who feel most threatened by any talk of change. It is politically short-sighted, and morally unacceptable, to imagine that any settlement from which they withhold their consent can work.
Instead of trying to deal with a disaffected nationalist community the two governments would have to confront an angry and possibly violent section of the unionist community which has already demonstrated its capacity to cause mayhem.
The suspicion which Tony Blair experienced in east Belfast is not confined to supporters of the Rev Ian Paisley. It is becoming clearer with each day that passes that political unionism is now hopelessly fragmented and this in itself adds to the community's fears about its long-term future.
The opinion polls show a clear majority of unionists in favour of David Trimble going into talks. But many moderate people to whom I have spoken are deeply pessimistic about the Ulster Unionist Party's ability to represent their interests. They cite the obvious pressures on the leader, the divisions within his own party, the lack of political resources and any clear strategy for combating the massed ranks of the pan-nationalist front.
They wonder who will provide Trimble with "covering fire" when hard choices have to be faced and worry that Tony Blair has no conception of the difficulties that lie ahead, though this may have changed as a result of Monday's foray into east Belfast.
The scenario they most fear is that we could have a settlement which is put to a referendum next summer - in the run-up to Drumcree - with Paisley and Bob McCartney campaigning against it. What will happen if this is passed overwhelmingly in the Republic but with a very narrow majority in the North, i.e. by a combination of nationalist voters and a minority within the unionist community, leaving an angry and disaffected majority of unionist voters outside the consensus?
I know very well that there are also pressures on nationalists, particularly on Sinn Fein. But anyone who was at Stormont last Monday could not have been left in any doubt that it was the unionist parties which were feeling the strain of the day's events.
Against this background, David Andrews's first appearance at the talks - and the fact that he put a private meeting with David Trimble at the top of his agenda - was doubly welcome. It may be that this encounter will turn out to be at least as important as Tony Blair's historic handshake with Gerry Adams.