THE exchange was short and a little unpleasant.

"I want a word with you," the former Cabinet Secretary for Education Michael Russell hissed as he passed me on his way out of the conference hall.

A frank exchange of views at fairly close quarters ensued with neither party giving much ground.

The issue was the Scottish Government's class size policy and a Herald article where comments by Mr Russell had been interpreted as an admission that the strategy was undeliverable because councils could simply ignore it - as some had already been doing.

Mr Russell was keen to point out that what he had been trying to explain was that the nature of democracy in Scotland meant local authorities would always have flexibility over the delivery of Scottish Government policy.

What I learned that day, apart from the fact Mr Russell was an avid reader of the press, was his attention to detail and an appetite for direct confrontation when he deemed it appropriate.

It was a style that undoubtedly made him enemies in the years that followed our 2010 corridor contretemps. At one stage, MSPs from Labour, the Conservatives and the Liberal Democrats combined to call for an investigation into what they called a culture of "secrecy, bullying and intimidation" in Scottish education.

But it was also a style that, combined with his intellect, enabled him to grapple with the powerful vested interests of Scottish education as an equal and, as a result, make some very significant contributions.

As Mr Russell now bows out to Holyrood's backbenches after the latest cabinet reshuffle it seems appropriate to judge his contribution.

Perhaps the sector least happy with his tenure is further education, where wholesale restructuring and the cutting of jobs and student numbers has left many fearing for the future. Universities too have their gripes, with concerns from principals over the creeping centralisation of power.

But the positives are also tangible. For the first time universities have been challenged on their record on equality of access, with new outcome agreements demanding immediate and identifiable improvements to the number of students from the most deprived backgrounds in Scotland they recruit.

Perhaps Mr Russell's greatest achievement was the work he did to help deliver the Curriculum for Excellence (CfE), which was in a shambolic state when he took over.

Teachers had little idea what was expected of them and the bodies in charge of delivery, such as the former Learning and Teaching Scotland quango, seemed hopelessly adrift, hiding behind a wall of indecipherable education-speak which even they didn't seem to understand.

It is too early to judge whether CfE will deliver the benefits to Scottish pupils that have been promised, but what can be said is that Mr Russell's unwavering support and strong political leadership, allied to his understanding that he needed to listen to the concerns of trade unions and act upon them with greater levels of classroom support, probably helped save it from disaster.