Written by Michael Trevelyan
The Use of Single Joint Experts
Most practitioners, particularly in personal injury or disease cases, will be familiar with the concept of a Single Joint Expert (“SJE”). As a consequence of CPR r. 35.1 and 35.7 the use of expert evidence must be restricted to that reasonably required to resolve the proceedings and one very common way of so restricting the evidence is for the Court to order that the parties jointly instruct a SJE. A SJE is, as the name suggests, one expert instructed by both parties with instructions to report on a particular issue.
In most cases where a SJE is instructed, their written report will be all of the expert evidence required on the issue and may well be determinative of the case. The hope is that both parties will remain content with the SJE throughout and will be happy to accept their objective, expert conclusions.
Is A Party Stuck With A SJE That They No Longer Want?
The short answer is “no”. There are certainly cases in which both parties genuinely and in good faith seek to instruct a SJE but then one or other may decide that they no longer wish to rely on their evidence. This could be for any number of reasons but quite commonly the SJE may produce a report which contains conclusions adverse to one party which then seeks to obtain, and put into evidence, a second opinion that is more favourable.
In order to rely upon a second opinion from a new expert (“NE”) the party seeking to do so will need to apply for permission pursuant to CPR r. 35.4. The starting point with any such application should, as with most applications, be the Overriding Objective in CPR r. 1.1 which is so well known that it will not be repeated here.
There are two significant cases for the Court to consider when deciding on such an application. The first is Daniels v. Walker  EWCA Civ 508 which is particularly significant as it was decided shortly after the CPR came into force and therefore takes a more purposive view of the relevant principles than might otherwise have been the case.
Daniels involved a claim for personal injuries and care in which a SJE was initially instructed but then further expert evidence was sought from a consultant occupational therapist.
The most relevant extract from Daniels can be found in paragraphs 27 and 28 of Lord Woolf M.R.’s judgment, in which the following principles are set out:
“…Where a party sensibly agrees to a joint report and the report is obtained as a result of joint instructions…the fact that a party has agreed to adopt that course does not prevent that party being allowed facilities to obtain a report from another expert, or, if appropriate, to rely on the evidence of another expert.
In a substantial case such as this, the correct approach is to regard the instruction of an expert jointly by the parties as the first step in obtaining expert evidence on a particular issue. It is to be hoped that in the majority of cases it will not only be the first step but the last step. If, having obtained a joint expert’s report, a party, for reasons which are not fanciful, wishes to obtain further information before making a decision as to whether or not there is a particular part (or indeed the whole) of the expert’s report which he or she may wish to challenge, then they should, subject to the discretion of the court, be permitted to obtain that evidence.”
Therefore, it is clear from Daniels that the door always remains open to a party to seek permission to instruct their own expert and rely on their evidence. The reference in the judgment to “reasons which are not fanciful” would also seem to impose a relatively, and perhaps surprisingly, low threshold test for granting such permission. It is tempting to seek to draw a parallel between that phrase and the test for defeating a claim for summary judgment, that the respondent’s case be ‘better than merely arguable’.
However, Daniels was undoubtedly a claim of complexity and high value. Lord Woolf M.R.’s judgment refers repeatedly to there being a “substantial” sum in issue and this has led many respondents to applications to instruct a NE to argue that the Daniels test is not applicable in more modestly valued claims.
The second significant case is that of the High Court in Bulic v. Harwoods  EWHC 3657. In Bulic the Court identified a series of propositions which can be summarised in the following way:
(a) Dispensing with a SJE will be more appropriate where the issue requiring expert evidence is central to the case;
(b) Where the expert evidence is of a technical nature the Court will be more likely to dispense with a SJE;
(c) Where a party loses confidence in a SJE for good reason, a ‘balance of grievance’ test may be applied to the respective positions of the parties if additional expert evidence is not permitted;
(d) It is not necessary on an application to instruct a NE for the Court to determine the relative merits of the expert evidence;
(e) The value of the claim is a relevant factor but one of limited weight which can be outweighed by the relevance of the expert evidence and whether it is of a technical nature.
The first two propositions are self-evident and fact-specific so require no further consideration. The third proposition can in a sense be sub-divided into two questions; has the party lost confidence for a good reason and, if so, what is the outcome of the balance of grievance test?
Whether there is a good reason for losing confidence will depend on what evidence is put forward to explain the applicant’s reasoning. Evidently, simply disliking the expert’s conclusions will not be a good reason for losing confidence. However, if a report is sought from a second expert and they are able to make sensible, detailed criticisms of the SJE’s methodology or analysis then that can form a very sound basis for justifiably losing confidence.
If confidence has been lost for a good reason then the balance of grievance test nearly always supports the applicant. It is difficult to see how a party could have anything other than a legitimate sense of grievance if an SJE’s report is objectively flawed to a material degree. To require the applicant to carry on with just the evidence of the SJE would require the Court to close its eyes to the applicant’s understandable loss of confidence and that is unlikely to be compatible with the requirement to deal with cases justly pursuant to the Overriding Objective.
The fact that it is unnecessary for a Judge dealing with an application of this nature to analyse any competing expert evidence between a SJE and NE makes the applicant’s task simpler. It is not necessary for an applicant to show that the NE’s evidence would be, or is even particularly likely to be, preferred by the Judge at trial. It is sufficient for any competing expert evidence to be from a suitably qualified expert and, it is suggested, free from any glaring errors.
The final Bulic proposition is in many ways the most controversial and provides a stark contrast to the stance taken in Daniels. Respondents to applications of this nature will often cite the value of the claim as a basis to disallow further expert evidence. It is true that Bulic was decided before the Overriding Objective was amended in 2013 to place a greater emphasis on saving costs and ensuring proportionality but nonetheless Judges hearing applications to rely upon a NE should not be transfixed by the value of the claim, Bulic is quite clear that the main considerations are the relevance of the evidence and whether it is technical rather than whether it is obtained at a suitable cost. For example I have had repeated success in securing permission to rely upon a NE even in cases of low value noise induced hearing loss where the likely value of the claim is less than £5,000.00, a sum which is dwarfed just by the cost of obtaining expert evidence in many such cases. Of course, in many low value claims the costs involved in taking the claim to trial will be far in excess of the sums in issue regardless of whether a NE is instructed and therefore a respondent’s objection to NE on the grounds of cost can often be defeated by reference to the realities of litigation in ordinary claims.
Alternatives to Instructing A New Expert
There are limited alternatives to instructing a NE where a SJE is no longer suitable. The main way of challenging a SJE is by asking them questions pursuant to CPR r. 35.6 in order to encourage a more favourable reconsideration of the key issues. However, CPR r. 35.6(2)(c) is clear that, save where the Court otherwise orders or the other party agrees, questions can only be for the purposes of clarification and not to undertake cross-examination by correspondence. Tactically, it is often beneficial to ask questions in order to demonstrate on a subsequent application that steps have been taken to avoid the need to instruct a NE and, of course, questions may provoke the desired response and cause the party to regain faith in the SJE.
Another alternative is to cross-examine the SJE at trial. This is usually a very difficult strategy. There is no requirement for permission in order to instruct an expert for the purposes of providing guidance for undertaking cross-examination of a SJE but even with that help in the background it is often a very difficult task to successfully cross-examine an expert if the Court will not receive evidence from any other expert source.
The position is particularly challenging for Claimants who bear the burden of proof. If the SJE is the only expert on, for example, causation then it is a tricky task for a Claimant to seek to undermine a SJE on some issues but then still invite the Court to rely upon their evidence on other issues sufficiently to discharge the burden of proof.
The final option is to simply accept the loss of faith and the SJE’s evidence. In some cases this will mean abandoning or conceding a particular issue but it may well be that there are bigger issues still live that justify taking a pragmatic approach to a subsidiary point. In many cases however the SJE’s evidence will be determinative of the claim, or at least a substantial part of it, and therefore a view will have to be taken on whether to incur the costs of an application to rely upon a NE and progress the case to trial, which is likely to be on the multi-track if there is to be oral evidence from two expert witnesses, or compromise the claim on favourable terms to avoid incurring further costs.
If you have instructed a SJE and have subsequently lost faith in their evidence for a good reason then consideration should be given to applying for permission to rely upon a NE. It is quite likely that a Judge will initially be sceptical of the merits of such an application, particularly in low value claims, but if the relevant principles from the authorities are properly impressed upon the Court then a more positive conclusion may well be obtained.