Given the fraught, fractious and controversial nature of the abortion legislation, it was always likely that something unpredictable would happen during its glacial-like protracted passage through the Dáil.
The probability that Fine Gael would lose Lucinda Creighton was the worst-kept secret in town, and one-by-one the four other potential defectors from the party all indicated that they would obey - albeit with varying degrees of reluctance - the strictly imposed whip.
All eyes yesterday were on Fine Gael. With the result that nobody was watching Labour.
Everything seemed to be winding down for the night just before 5am as a vote was called on amendment 10 on fatal foetal abnormalities.
And then, amid a sea of government red lights voting against the amendment, flashed up a wholly unexpected green one. But it wasn’t shining out from the turbulent waters of Fine Gael, but from the Labour side who were for once ad idem on this legislation.
Heads from all sides of the chamber turned in puzzlement towards Clare TD Michael McNamara and assuming he had made a mistake, everyone waited for him to hastily change his vote. It happens quite often, and at 5am nobody would blame him for the slip-up.
But Michael just put his head back and stared through the glass domed ceiling at the brightening sky. The clock ticked down to zero, and the vote remained as it was.
A couple of seats away, Labour’s whip Emmet Stagg casually leaned over to him, clearly reassuring the deputy that the error could be rectified. Michael sat with his hand over his mouth. He looked upset as he repeatedly shook his head.
Realisation began to spread among his colleagues that something was amiss. They clustered around his seat. Waterford TD Ciara Conway began to loudly plead with him to admit it had been a mistake and that he hadn’t just voted against the government. For disobedience would be met with no mercy and he would join the quartet of Fine Gael rebel TDs on the Independent back-benches.
But Michael seemed adamant. He vanished from the chamber through a side-door, and many of his colleagues streamed out the main entrance, unwilling to speak to the equally confused media who were lying in wait.
Nobody had seen this one coming. There were none of the warning portents scattered about like snuff at a wake by the mutineers in Fine Gael before they went overboard.
All was confusion. And to make matters worse, party leader Eamon Gilmore was in the US on business.
A little while later, Emmet Stagg emerged to insist that Michael had told him that it had been a technical mistake and that he fully supports the government. Although the vote would stand, there would be no repercussions for the TD.
It was, said Emmet, “a genuine mistake.”
But from the vantage point of the press gallery in the Dáil chamber, it looked like a genuine decision, although perhaps a spontaneous one on the part of the deputy.
It was a late-night shocker. And now Labour are in the spotlight today. This bill was never going to go quietly into the night.