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Concurrent Evidence

Medico Legal


by Alec Samuels

The instructed expert will rarely need to appear at trial. Along the line the case will be withdrawn or conceded or settled. The expert may have made his report; he may have been in contact with his opposite number; there may have been a meeting of experts; there may have been a joint report; but in the event the case did not come to trial. If the case did come to trial the traditional procedure was probably followed. The expert called by the claimant was examined in chief by counsel for the claimant, or the expert’s report was tendered, and the joint expert report was available. The expert was cross-examined. The expert perhaps did not find the experience very satisfactory. The cross-examination may have been insinuating, subtly or not so subtly casting aspersions on the integrity, experience, standing and competence of the expert; or aggressive, challenging everything, and perhaps not in a very well-informed manner. The counsel may not have appeared to be too well briefed, not too well acquainted with the subject matter, not too well prepared, and constantly needing to refer to his solicitor and his expert. The judge might also have been getting “tetchy”. When the expert for the claimant has left the witness box there may have been an interval of hours, or days or even weeks before the same procedure was followed with the expert from the other side. Although the lawyers believe that the adversarial system is the best method for eliciting the truth of the matter the expert may feel uncomfortable, trapped in a system not compatible with his scientific methods, such that he
was not able to give of his best. The artificiality of the process seems to him to be alien to his professional approach to the resolution of difficulties and the search for the scientific truth. The lawyers are very much in control of the system, practising in their customary forensic environment, namely the court. So a different and comparatively new system of the giving of evidence by the experts is beginning to  emerge, namely concurrent evidence (sometimes unhelpfully called “hot-tubbing”), encouraged and commended by the Civil Justice Council.1

Concurrent evidence is commonly used in arbitration, and is familiar in specialist areas such as those tried in the Technical and Construction Court TCC. The concept behind concurrent evidence is that the two experts should give their evidence concurrently, together, simultaneously, preferably sat side by side at a table in front of the judge, with space for their laptop and materials. The questioning at the trial will probably be led by the judge, taking the evidence issue by issue, probably using the joint expert report as a basis, and putting the same or very similar questions to each of the experts in turn.

The judge is likely to appear to be, and in fact to be, less aggressive or less hostile than counsel, though no doubt he will be “searching”.The independent,
impartial and objective judge will show appropriate respect to the independent, impartial and objective experts. The experts are usually permitted or encouraged to question each other, in an orderly manner, and the process will take on more of a dialogue or conversation. The experts will feel more comfortable, more at ease. A good judge can be and should be both flexible and penetrating in his questioning, and in the conduct of the entire process. The experts should feel less defensive, more willing to engage in open discussion, more ready to agree. The crucial issues for the experts may more readily be identified, helping all concerned, making the respective tasks of the respective experts and the lawyers and the judge easier. The quality of the evidence should be better. As the experts move closer together in their opinions on the main issues so the opportunities for settlement or a sound decision improve. 

As experience is gained, the maximum flexibility should be built into the system. As always, careful co-operative and timely case management promotes the effective trial. The judge may order concurrent evidence but still prefer counsel to lead the questioning. He has to play a much more interventionist role, and must beware of the risk of subconsciously falling into his former role as a forceful advocate for a party. He may be willing for the experts to engage in mutual dialogue, or he may prefer all the questions and answers to follow the more traditional process and he may require all answers to be addressed to him. In concurrent evidence the uncontrolled expert witness could wander off into irrelevant matters, at least legally irrelevant matters.

Whether or not concurrent evidence for the experts is followed in any particular case is for the judge. Ideally the judge should be experienced and well disposed to the process, the parties should agree, and the forward preparation of some sort of agreed agenda will prove to be useful, based on a clearly written joint expert report. For the judge to impose the process upon the lawyers acting for the parties, and without giving good reasons, would probably be unwise, as friendly co-operation greatly smooths the process.

In order to make concurrent evidence a success the judge will need to be familiar with the relevant area of the law and the special field of expert knowledge, e.g. construction or shipping or accountancy or personal injuries, so an appropriate judge should be allocated to the case by the listing officer, and preferably a judge able and willing to participate in the concurrent process. Also careful and thorough pre-trial preparation by the judge will be essential. He cannot come “cold” to concurrent evidence.


All the indications are that the time taken for the experts to give their evidence is shorter under the concurrent system than the traditional system. The shorter the time taken in the court room the less the direct and indirect costs. Though the longer the time taken in pre-trial preparation the more the direct and indirect costs in the pre-trial process. So concurrent evidence may be better evidence, but compared with the traditional procedure may in fact be cost neutral.

Expert prepared

If concurrent evidence is to be followed the expert should be informed at the earliest possible moment so that he may not be taken by surprise and may prepare himself accordingly. He must be prepared to engage in dialogue with the expert on the other side and the judge, and to appreciate when a modification of opinion or a concession is or is not called for by the science of the discipline involved.


There are situations where concurrent evidence would appear not to be suitable. Goodwill must be a feature of successful concurrent evidence. Therefore if a party wishes to challenge the integrity or credibility of the opposing expert, the challenge is more than a professional difference of expert opinion, there is animosity in the air, then much better to follow the normal traditional process, keeping the expert witnesses well apart. The matter should be raised pre-trial.

Where the expert does not have the character and personality and reputation of the expert on the other side, or does not readily engage in inter-expert dialogue, then concurrent evidence is to be avoided if possible.


The lawyers, especially the advocates, or some of them, are sceptical or dislike or are positively hostile to concurrent evidence. The advocate likes to control the conduct and the presentation of his case, and likes to control his witnesses, so as to ensure the most favourable impact upon the judge. If the judge has led the questioning, and the experts have engaged in forensic dialogue, further cross-examination may have little point, the opportunity to undermine the expert for the other side has greatly diminished.

Encourage the expert

In view of the difficulty in finding an expert to accept instructions, perhaps because of dislike of the traditional process and a feeling that the system does not enable him to give of his best, as well as the fee problem, the emerging concurrent evidence system may encourage the reluctant expert to accept instructions and to feel that he can comfortably give of his best.

The modern online digital court 2

As the modern on-line digital court envelops the legal system the participants in the trial will no longer need to meet together in the court room. Skype or skype model 2 will enable the judge, counsel, solicitors, witnesses and experts all to remain in their office or home and fully to participate, a process starting in the smaller value claims, up to £25,000, but inevitably in due course covering the larger value claims, where the experts appear. Concurrent evidence will be well suited to the new legal age.


1 Rule 35, Practice Direction and Guidance Note. Concurrent Expert Evidence and “Hot-tubbing” in English litigation since the Jackson Reforms, Civil Justice Council, 1 August 2016. Changes to the rule, practice direction and guidance are expected in 2007, with a new Information Note for Expert Witnesses. Body of Evidence, Alec Samuels (2016) New Law Journal 16 September 2016 p 21.

2, Civil Courts Structure Review, Lord Justice Briggs, 27 July 2016.


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