The observant onlooker, noticing his garb, might think him a lawyer, maybe even a QC. But it is one of the pleasures of living in a smaller jurisdiction that our senior judge, Lord Hamilton, moves about the capital on foot and unnoticed - and a million miles away from the media spotlight. So, all the more reason to sit up and pay attention when he departs from his usual cautious modus operandi and launches a counter-blast against the SNP administration and its assault on judicial independence in the wake of the collapse of the World's End trial.
What caused our senior judge to vent his concerns? In a lengthy defensive statement to the Scottish Parliament following the debacle, Lord Advocate, Eilish Angiolini QC, ministerial head of the prosecution service, made but a cursory genuflection towards the constitutional importance of an independent judiciary while expressing a view on one judge's decision.
Given their avowed position (there was a surfeit of evidence against the accused), prosecutors might have done better to explain their failures to bring that evidence out before a judge who already had made clear his concerns. Instead, evidence already before the jury was taken back from them by decision of the prosecution - not the judge. The trial judge faced an unhappy choice: allow a high-profile case to proceed or do as he believed the law required and let the prosecution collapse. A testing predicament for any judge and just the sort of circumstances that demands sober commentary on the role of our judiciary.
It would be naive to expect judicial decisions to escape scrutiny. A robust Lord Advocate rightly might defend the decisions of her prosecution team. But here the trial judge, wholly as a result of prosecution conduct, was accused in the parliament of having made the wrong decision in halting the trial. The judge properly made no comment. We were told by Ms Angiolini that his approach departed from the prosecution's preferred script: "I am of the clear opinion that the evidence made available to the court was sufficient to be put before the jury." As our legislators rushed to comment, none seemed to notice a boundary had been crossed. If it is sufficient that the Lord Advocate, not the judge, is content on the sufficiency of evidence - what need for judges?
Despite their antics, Scottish ministers missed the fact they had enjoyed considerable luck regarding this terrible case. Even were Lord Clarke wrong - there has yet to be a compelling exposition from any source that he was - the responsibility for his decision being the final decision in the case rests solely with ministers not the judge.
This was not just a matter of past indifference - as she stood up in parliament, Ms Angiolini knew no instructions were with the parliamentary draftsmen on a bill introducing Crown appeals in such cases. As he listened, Alex Salmond, the First Minister, knew no proposal had been made by him and no room for any such provisions had been made in his legislative programme. Both had evaded the public fury that might have erupted had this been a recent child murder, not a tragic murder some 30 years old.
Yet a very dangerous situation maintains. Misplaced public criticism of courts and judges - not least by elected or appointed ministers - threatens judicial independence. Judicial independence from the dictates of the executive is a cornerstone of our democracy. US jurist Anthony Kennedy encapsulates its necessity: "Judges must be independent not so they can do as they choose, they're independent so they can do as they must." The World's End case is the "hard case" that demonstrates the pressures exerted on judges in decision-making. Should we expect judges, just because the result is unpopular, not to do their duty? Is a certificate of sufficiency from the Crown is enough to establish guilt?
In her reply, the Lord Advocate seemed to suggest her actions had not been intended as an attack on the judiciary. Yet we need to ask the question - who might best assess the state of judicial independence? Embattled ministers defending their debacle in the bear-pit of Scotland's Parliament or our most senior judge, speaking with the agreement of our second most senior judge, and doing so on behalf of all the senior judiciary? There was no mischievous plot here to undermine the judge, still less strong-arm another decision out of a conscientious judge going about his duty. It seems more probable the current falling out owes more to profound constitutional illiteracy on the part of the ministers. That it was illiteracy not malice that brought us here is no consolation: the result is the same.
• Brian Fitzpatrick is an advocate and former Labour MSP for Strathkelvin and Bearsden.