There was palpable excitement in the press conference room on 28 January 2004 as the camera crews’ set-up their equipment and journalists took their seats in anticipation of the findings of the Hutton Inquiry into the actions and events that culminated in the suicide of the Ministry of Defence’s biological weapons expert, Dr David Kelly.

How much damage would be inflicted on the reputation of Tony Blair’s government? Although Alastair Campbell had already resigned as Blair’s director of communications, it was widely expected that he would be singled out for opprobrium and the only question was how many others would be tarnished by his disgrace. Might even the prime minister take at a collateral hit? Seasoned observers thought it likely.

And then Lord Hutton took to the podium and began to delivery his verdict. Looks of disbelief, bewilderment and horror began to steal across the assembled journalists’ faces as they realised that far from exposing the rotten core of government, the judicial inquiry had examined it closely and found hardly any evidence of wrongdoing. Resignations did follow – but they were those of the chairman and director-general of the BBC.

The heightened expectation that a law lord would get to the bottom of things better than other forms of investigation partly explained the broad expectation placed in Lord Hutton that he would come up with the goods. “Partly explained” because this expectation was also a product of hope amongst those who felt that Tony Blair and his inner circle had conspired in a wicked misadventure in Iraq and any searching inspection of their associated actions could hardly fail to uncover maleficence.

So the Hutton Inquiry comes readily to mind with the verdict – delivered seventeen years later – of another eminent Irish lawyer, James Hamilton QC in finding no breaches of the ministerial code by Nicola Sturgeon in the strange affair of Alex Salmond. As recently as yesterday, there was a building expectation – and from many, undisguised hope – that he would weigh Scotland’s current First Minister in the balance and find her sorely wanting. Instead, Hamilton finds all her explanations, whether for her actions or her omissions, wholly plausible.

This is a sweeping exoneration. In delivering it, Hamilton has certainly spiked-the-guns of the Holyrood Inquiry whose report was scheduled for publication on Tuesday. Having been partly leaked, we already know that it divided along party lines with the (non-SNP) majority uninclined to give Sturgeon the benefit of the doubt. SNP briefings have already been at work, dismissing the Holyrood committee’s work as that of a partisan lynch mob that was determined to “get” Sturgeon regardless of where the evidence led. It is – Sturgeon and her supporters insist – the “independent” adjudication of James Hamilton that matters.

victory on the Western Front will not come via a bombardment of the Dardanelles

Opposition politicians, particularly the Scottish Conservative and Liberal Democrat leaders, Douglas Ross and Willie Rennie, have pointed out that Hamilton declared that it is up to Holyrood to decide if it accepts his assessment that Sturgeon’s “incomplete narrative of events” (particularly her mis-stating when she learned of the harassment complaints against Alex Salmond) was unintentional and not a breach of the ministerial code. The Conservatives’ motion of no confidence in Sturgeon being tabled on Tuesday provides Holyrood with that invitation to deliver its verdict. With the Greens backing the SNP, it is already clear that Sturgeon will survive parliamentary censure. More than that, she may turn the occasion into a barnstorming vindication against her tormentors.

The wider question is now whether the SNP’s popularity – which has dipped in recent weeks – may enjoy a bounce. That would be an extraordinary turnaround from the sense of certainty expressed by so many Opposition politicians and their well-wishers that they had the Nats on the run and it was only a question of which would be the better result – Sturgeon forced to resign, or Sturgeon limping on but seriously bruised.

They will get neither wish. The damage to be inflicted upon the First Minister now can come only from her enemies within the SNP and from the ability of Alex Salmond to – within the Crown Office’s constraints – conjure up further revelations of a magnitude to make fair-minded people think that perhaps James Hamilton was not in full possession of the facts when he found in Sturgeon’s favour.

The immediate lesson for unionist politicians is that victory on the Western Front will not come via a bombardment of the Dardanelles. In other words, the strength and appeal of Scottish nationalism will not be defeated by some side manoeuvre concerning whether the previous leader of the SNP or the current leader of the SNP has provided a more accurate account of the circumstances surrounding their mutual antipathy.

There are six weeks to go before Scotland’s voters head to the polls. The surprise knockout blow having failed, the pro-union parties have left it late to decide how they are going to fight the Nationalist hyper-power. The personalised attack has been repelled. And, in any case, when it comes to personality, what have the unionists to offer? Does Douglas Ross look or sound like a First Minister?

The unionist parties have bet heavily on an outcome that has not come up trumps. This being so, do they advance towards the Nationalists’ preferred battleground of IndyRef2 in the belief that roughly half the electorate will not support a party determined to have another referendum and they can spit that 50 percent between themselves and call that a good result?

Or can the unionists articulate convincing solutions to the myriad policy failings that fourteen years of SNP-led government has bequeathed Scotland. They have failed to do so all this time. It should not be assumed that this is because they must be saving-up the big ideas to the last weeks of campaigning. No wonder they wanted James Hamilton QC to do the difficult work for them.