How quickly an innovation can become part of the furniture. The aftershocks that followed the decision of the UK Supreme Court in the case of Peter Cadder have led to emergency legislation in Holyrood, The Criminal Procedure (Detention, Legal Assistance and Appeals) 2010 Act, and the commission of a full-scale review of the rights of anyone detained by the police in Scotland on suspicion that they have committed a crime.
In the often unhelpful polarisation of the ensuing commentary between the rights of the suspect and the interests of victims it is easy to overlook how recent the concept of "detained person" is, invented in the course of the deliberations of the Thomson Committee in 1975 and enacted in 1980.
"I started my legal career in the pre-detention era," says Lord Carloway, now enjoined by the Justice Secretary to make sense of the post-Cadder situation. "When I was defending people in the late 1970s we were in what could be called 'the Chalmers era' where there was either arrest or liberty. I saw detention introduced and have seen its effects from the perspective of both defence advocate and prosecution advocate depute."
And, of course, the perspective of ten years on the bench in the High Court and, more recently, as the administrative judge sifting prospective criminal appeals.
It is apparent that Lord Carloway's copy of the Thomson Committee report has been well thumbed in recent weeks as he prepares to revisit the arguments that have been overtaken by the UK Supreme Court following, in turn, the deliberations of the European Court of Human Rights in 2008 in the case of Salduz v Turkey.
"We have to go back and look at the principles the Thomson Committee considered and see where they are relevant now," says Lord Carloway. "Should we have a separate process called detention at all? Should there be something separate from arrest? And whatever the status we recommend, what rights do we need to give the police to question a suspect and what protections have to be put in place for the person detained? We have to determine the minimum requirements set out by the European Court in Salduz and then consider how the balance should be constructed within the expectations of our society in Scotland."
Determining expectations is often like grasping jelly. It looks to have substance until you try to take a firm hold of it. It has been a matter of some pride, sometimes justified, that elements of Scottish practice and custom have been at the quirky to unique end of the international spectrum of criminal procedures.
The Thomson Committee reconfirmed several of them. It may be that a century and a half of legal nationalism is winding down under the gaze of judges outwith the confines of Parliament House.The Scottish approach to corroboration, the requirement that there should be independent sources that can address a particular piece of evidence, will come under scrutiny not only because admissions made during those pre-Cadder interviews of suspects by police often produced admissions that became the second source.
"Is corroboration in the melting pot? Yes," says Lord Carloway. "It is in my terms of reference and will therefore form a significant part of the review. Every sophisticated system of criminal law works on a system of checks and balances. Are the protections we have relied on previously appropriate now in a system which has had additional safeguards introduced into it following the Supreme Court judgment. Corroboration has been a cornerstone of the Scottish system for a long time - and a matter of considerable pride - in assessing sufficiency of evidence.
"I'm not aware of any other country in Europe that has such a strict concept of corroboration as we have had. If we conclude the concept should be adjusted we will have to set out a new test for sufficiency of evidence."
Lord Carloway's initial terms of reference for his review were amended in the wake of the debate in the Scottish Parliament on the emergency legislation to allow him to consider the issues that had arisen in the sprint to the statute book.
In particular, there were misgivings from several parts of the chamber about the inclusion of section 7 of the new act which created a section 194DA of the Criminal Procedure (Scotland) Act 1995, and appeared to introduce a fundamental change in the relationship between the court of appeal and the Scottish Criminal Cases Review Commission. While the explicit intention of the Scottish Government appeared to be to bolt the door on prospective appeals against past convictions based on admissions made in interview during detention, the concern is that it has given the appeal court a new power to refuse to reopen any case even when a prime facie case has been made by the SCCRC that a miscarriage of justice has occurred.
Its chairman, Jean Couper, issued a public statement - unprecedented for the SCCRC - expressing her concern at section 7.
Lord Carloway says, "At the appeal court we only had one test which is whether there had been a miscarriage of justice. That was case specific. If there was an argument that a miscarriage of justice had taken place we would have to allow the appeal. The commission has two tests to apply - whether there had been a miscarriage of justice and whether it is in the interests of justice that the case be referred to the court of appeal."The emergency legislation gives the appeal court an additional 'interests of justice' test to apply and I understand that the commission is concerned that effectively there are now two gatekeepers.
"I don't have a settled view on 'conclusivity' but we will be looking at the issue as part of our review of the act. That's why I invited someone from the SCCRC to be part of the reference group."
While revisiting the work of the 1975 Thomson Committee Lord Carloway is explicit that his review will be entirely different in approach and procedures.
His first interim report is due to be delivered by March, breakneck speed for this sort of project.
"I don't see our efforts will be a turning point in the same way the Thomson Committee was," he says.
"It was a large committee that reviewed matters from all angles in search of a consensus. We won't get bogged down in prolonged debating of that sort. I think they had 122 plenary sessions of the whole group.
"I will be working effectively full time on this with a full-time staff of four, including a lawyer from the Crown Office and one from the Scottish Government legal directorate. We will have a reference group and have invited some individuals and nominees from a range of relevant agencies and professional groups to be on it. The Thomson Committee was rather judge heavy but we have invited only a nominee from the Sheriffs' Association, as well as myself from the bench.
"We also have an extensive list of consultees but I expect there will be only half a dozen meetings of the whole group. I prefer to bring small groups in to contribute their wisdom on specific issues.
"I'm not going to be chairman or umpire. The reference group is not going to be asked to form a consensus on any of the issues. On some it may not be possible. There will be some controversial aspects to the ultimate report. They are going to be asked to criticise what I say and appraise the thinking as it develops. But the report itself is going to be mine and I will take responsibility for it, good or bad.
"Whether it is accepted or not - that will be for the political parties to take on."