It was only a passing grin, a scintilla of a smile.
The first minister was contemplating the prospect that, post election, he might still be in a position to answer questions as . . . first minister.
Otherwise, this was a notably solemn interrogation session. Perhaps that was partly prompted by reflections upon global events.
Jamie Stone told the chamber of a Scottish oil worker trapped in a flat in Tripoli.
The Presiding Officer Alex Fergusson told MSPs that he had written to his New Zealand counterpart to offer sympathy for the earthquake victims.
But also it was those impending elections.
Each of the opposition leaders took the opportunity to pursue issues which they intend to use in the campaign.
In response, Alex Salmond was, quite deliberately, constrained, even subdued. His plain intent was to sound serious and governmental.
The issues? For Labour's Iain Gray, knife crime.
Mr Gray cited individual tragedies which, he said, each argued for mandatory jail sentences for carrying a blade. His pitch was passionate and, he hopes, popular.
In response, Mr Salmond set out action taken by his government which, he said, had successfully reduced violent crime: not least, recruiting more police.
Right at the close of the exchanges with Mr Gray, the first minister adduced evidence from a senior police officer to the effect that prison was far less effective than intervention to tackle Scotland's booze and blade culture.
For the Tories, Annabel Goldie addressed the issue of delayed discharge from hospital.
For the Liberal Democrats, Tavish Scott pursued his argument that local accountability would be threatened by moves to reduce the number of police forces.
To each, Mr Salmond offered a notably measured reply.
No indignation, no counter-attacks.