Expert witnesses giving concurrent evidence – or ‘hot-tubbing’ – should be the default position in the Mercantile Court and Technology and Construction Court (TCC), the Civil Procedure Rule Committee (CPRC) has suggested.
It was giving direction to a sub-committee that had told the CPRC that hot-tubbing had not caught on and was not widely taken up voluntarily.
The sub-committee was set up, under the chairmanship of Mr Justice Kerr, to consider a report last summer from the Civil Justice Council (CJC).
This found  that, where it was used, hot-tubbing improved quality, saved trial time and helped judges determine disputed issues.
The CJC report called, among other things, for a re-drafted version of PD35.11 (on concurrent expert evidence), a new guidance note for judges and practitioners, and a new information note for expert witnesses.
In the sub-committee’s report to the February meeting of the CPRC – papers from which have just been released – Kerr J said that in general hot-tubbing had not caught on, was not the default position, and was not widely taken up voluntarily.
It recognised the danger that implementing the CJC proposals would not deliver hot-tubbing unless it was imposed through the rules or standard directions and the onus was on a party to opt out.
Kerr J recounted that, shortly after the sub-committee met, he tried a clinical negligence case “which was a paradigm case for hot-tubbing”, as it involved four cancer experts who gave oral evidence. “There was wasteful duplication of effort and cost,” he said,
The judge continued: “To my frustration, it proved impossible to hot-tub the experts. When I raised the issue with the parties at the start of the trial, one counsel was very hostile and the other (quite junior) looked blank as though he did not know what hot-tubbing was.
“Concurrent expert evidence had not been considered by the parties and appeared alien to their culture and experience of litigation.
“The CMC [case management conference] directions had not included any hot-tubbing direction. The trial had been timetabled for the experts to give evidence separately (sequentially by discipline).
“The evidence was complex and difficult. My preparation time for the whole case was less than half a day, wholly inadequate to include preparing for a hot-tubbing session in court on unfamiliar and difficult medical issues.”
The sub-committee’s report continued: “It appears that unless hot-tubbing is actively promoted and the parties warned that it is likely to be imposed on them, it may make little headway, at least in more generalist jurisdictions such as personal injury and clinical negligence.
“The position may be different in high end specialist jurisdictions such as patents, TCC and heavy commercial litigation.”
It added that there was a concern – in personal injury and clinical negligence cases at least – that “we risk putting the cart before the horse if we try to promote hot-tubbing without first reviewing more widely how the current CPR part 35 and PDs work in practice and whether wider change is required, for example to the joint discussions and joint statement procedure; especially given the absence of early judicial allocation to such cases in the QBD and county courts”.
The sub-committee asked the CPRC for a steer, including whether it should go further than the CJC report to promote and increase use of hot-tubbing.
The minutes of the February meeting recorded the CPRC’s view that dictating the use of hot-tubbing “would be a step too far but that certain types of cases could be identified where it should be the default position”.
The minutes said: “It was suggested that the standard directions or the judicial template for directions could be used to flag up hot-tubbing with parties before the CMC.
“In two courts, the Mercantile Court and the TCC, where the case management is handled by the trial judge, there is the opportunity to address hot-tubbing at an early stage and cases in those courts are such that hot-tubbing is an appropriate tool.”
The CPRC tasked the sub-committee with identifying specific classes of case or types of issue requiring expert evidence for determination, and indicating whether hot-tubbing was appropriate.
Where it was appropriate, the sub-committee should then consider how it should be raised with the parties, and where and how it should take place as part of judicial case management process, or separately.