The prime minister's official spokesman Tom Kelly had hardly got the words "we are still in business" out of his mouth when he was interrupted by an unmistakable sound from across the green at St Andrews.
"Cockadoodle doooooooooo," went the rooster. The media, and the spokesman, erupted in fits of laughter. As the media looked at Kelly as if he had been caught out, he protested: "There's two more to go!"
As many an author would say: "You couldn't write it!"
Cynical reporters who were used to Downing Street spin took the positive briefing with a rather large dose of salt, but were intrigued that the talks, due to end at noon on Friday, were going to go into the afternoon.
Ian Paisley walked hand in hand with wife Eileen
As most reporters - and politicians - made new travel plans, it seemed as if it was going to be another bumpy negotiation with an uncertain outcome.
The Sinn Fein leader had already teased the media earlier. When asked serious questions about the negotiations, Gerry Adams only wanted to talk about the beautiful weather.
And for once, Ian Paisley said nothing, content to walk hand in hand with his wife Eileen in what was essentially was a photocall to mark the couple's golden wedding anniversary.
Normally negotiations rise and fall, fall and rise, with a shift here and a shift there.
But in the words of one SDLP insider, St Andrews was the "oddest negotiation" he had ever been to. The press corp would have to agree. Said another: "This one went from zero to 500!"
The night before, the DUP was saying no privately and was equally adamant first thing in the morning that there would be no shadow ministers by 24 November.
Then there was a hint from some unionist insiders that Sinn Fein was moving on policing. But before confirmation of a republican shift had even come, the deal had arrived.
Was it all pre-cooked? Did Ian Paisley go there expecting to come out with a deal? Did the prime minister - and the taoiseach?
They certainly produced much more than the meek heads of agreement being whispered about with more hope than expectation.
Was St Andrews all a choreographed dance?
How could they have gotten such detail together when the prime minister and his staff were distracted by crisis over Iraq and when the participants were bitterly complaining to the media that there was no organisation and the talks were a bit of a shambles?
Was the sign that said St Andrews Agreement ordered just in case or in expectation that the dance would end successfully? Is there a sign somewhere, unused, that said Leeds Castle Agreement?
Or was it, as one insider darkly whispered, that someone from the Dublin camp, had spelled out to the DUP what plan B meant - and there was no option?
The problem with that theory is Ian Paisley did not look like anyone had just threatened him.
The jokes about Friday the 13th are flying fast - a real freaky Friday. But there is no sign as yet that the DUP leader is going to "change back" to his old self.
The only voice out of St Andrews that was really upset was Robert McCartney's. "Worse than the Good Friday Agreement" was his angry verdict. But what can he do about it? What will he do about it?
"The biggest obstacle will be tying up loose ends"
As things stand, there is no strong opposition - no-one with Ian Paisley's power - to tackle the DUP leader.
The Ulster Unionists are not really in a position to criticise and too much criticism sounds like sour grapes. The biggest obstacle will be tying up loose ends, and overcoming the inevitable events that try every politician.
Just why Ian Paisley shifted so quickly at St Andrews when others, including this correspondent, were predicting that he would take much more time to cut the deal, will perhaps take more time to clear up.
The DUP leader himself spoke of a crossroads, in his address - echoes of Terence O'Neill's famous television address when as prime minister in 1968 he pleaded for moderation and declared "Ulster was at the crossroads."
Have those words haunted Ian Paisley or was it another odd coincidence that he used them?
Unlike Gerry Adams's emotional admission about republicans being part of the problem, Ian Paisley has not admitted to any past mistakes.
But it seems certain that he won't repeat the mistakes of David Trimble, who sometimes sounded like he was in the no camp.
The DUP leader has signalled that he will be fully committed to his pledge if Gerry Adams's answer is yes. What better day to demonstrate your ability to commit to your new political partner than on your golden wedding anniversary?