Contrite apology from Salmond
Alex Salmond is accustomed to dominating the Holyrood chamber with elevated rhetoric. Tonight the tone is one of contrite apology.
At issue is the first minister's plan for a two question referendum on Scotland's constitutional future: independence plus the option of devo max.
A leading academic, Dr Matt Qvortrup, told The Times that such a plebiscite, as set out by the Scottish government, was potentially confusing in that it gave equal status to two issues which might be thought to be contradictory.
Towards the end of first minister's questions, Mr Salmond indicated that this criticism had been retracted by the academic.
However, it subsequently emerged that Mr Salmond had, inadvertently, got it wrong.
The quotes the FM had delivered had actually come from a draft suggested by Mr Salmond's own adviser.
Cue anger from opposition leaders. In news statements, in points of order, in interviews, they demanded clarification.
Mr Salmond has probably ended the row for now, not least by offering a swift apology and by doing so in a relatively humble fashion”
The first minister, they argued, was guilty of misleading parliament and of seeking to nobble a critic.
There had been no intention to mislead parliament - but his comments had been wrong, based upon a misinterpretation placed by him upon information he had received immediately before entering the chamber.
Crucially, he said the error was his - and his alone. In short, he would not allow public blame to be cast upon his staff.
Smiling now, Mr Salmond said he had subsequently spoken to Dr Qvortrup - noting that he should perhaps have done so before first minister's questions.
Dr Qvortrup accepted that a two-question referendum was possible - provided certain conditions were met. And he was willing to act as an adviser to the Scottish Parliament.
So what are the conditions? Broadly, that independence and devo max should be placed in conflict, not in continuum.
Dr Qvortrup will suggest in a letter to The Times for publication tomorrow that, while it was "always an honour to help the press", the full content of his views did not feature in the original article.
In summary, he believes that having two questions of equal weight would be unusual and not advisable.
He suggests instead the "New Zealand model".
Under this, people in Scotland would be asked first if they wanted change - then asked to choose between devo max or full independence.
So where are we tonight? Mr Salmond has probably ended the row for now, not least by offering a swift apology and by doing so in a relatively humble fashion.
Some opposition critics are complaining that he apologised with a smile, that he has yet to grasp the controversy.
For myself, I thought his smile was one of wry acceptance of his situation.
But the longer term controversy over the nature of the referendum will continue.
To be clear, Mr Salmond is not absolutely intent on such an approach.
He says only that devo max is a "legitimate" proposal for inclusion - if it has evident support.
Perhaps Mr Salmond will now be more ready to listen to the advice of Margo MacDonald, who said he should stop "piddling about" with a second question and stick to the issue of independence.