Dis-Instructing a Single Joint Expert in favour of a Sole Expert
The Claimant brought a claim for damages against the defendants for a serious, mechanical engine failure in his car. The critical issue between the parties was the cause of the engine failure. The Claimant asserted against the garage (the 1st Defendant) that the fault lay with poor servicing; and against the manufacturer (the 2nd Defendant) that there was a design fault in the engine. The Defendants contended that the engine had failed because it had been over-filled with oil.
A single joint expert was instructed to report to the Court on the cause of the engine failure. The Claimant concluded that the report of the Single Joint Expert (“the SJE”) was flawed, that the SJE lacked sufficient expertise, and that she was biased. The Claimant therefore applied for permission to call his own expert witness, and for the single joint expert to be dis-instructed. The Claimant produced a report which doubted the SJE’s technical expertise and reasoning in support of the application. The judge at first instance rejected the application.
The Claimant appealed to Eady J. The appeal was advanced on four separate grounds.
The first was that the judge had applied the wrong test as to whether a party would be allowed to call his own expert, despite a prior order for an SJE. Eady J examined the cases, starting with Lord Woolf MR’s judgment in Daniels v Walker  1 WLR 1382, and held that the authorities showed that requirement was simply for the applicant to show a “good reason” for instructing his own expert. That would depend on the facts of each case. Since the judge at first instance had misunderstood those authorities as imposing a higher requirement, and refused the application on the basis that permission would only be granted in an “exceptional case”, that afforded a good reason to allow the appeal.
Eady J also had regard to Lord Woolf MR’s judgment in Peet v Mid-Kent Healthcare Trust (Practice Note)  1WLR 2010, in which the CA had held that permission to a party to call its own expert would be more readily granted if the issue dealt with by the SJE was central to the case. That was the position here, and the judge had not given sufficient weight to that factor.
Eady J rejected the second ground (bias). The SJE was experienced and acted for both claimants and defendants. The fact that she had been instructed by the defendant previously was not a ground for alleging bias.
The third ground was that the judge at first instance had erred in rejecting the criticisms of the SJE made by the Claimant’s proposed new expert. Eady J noted that the judge had dealt with these in detail, but that on balance they should be a matter for the trial judge after hearing both experts cross-examined. In doing so, Eady J applied what in Kay v West Midlands HA (unrep.), HHJ MacDuff QC had called the “balance of grievance” test, and decided that the importance of the claimant being able to advance a case on the basis of expert advice he considered acceptable was greater than the inconvenience to the defendants having to deal with another expert.
The last ground was that the judge at first instance, applying comments made in Dennis v Walker, had decided that it would be inappropriate to permit the claimant to call a further expert because the case was not “substantial” in value. Eady J rejected this approach, holding that Lord Woolf MR’s comments in Dennis v Walker were not intended to lay down a mandatory set of principles, and that “substantial” would not always mean “substantial in value.”
In the circumstances, the appeal was allowed, and the claimant was permitted to call his own expert.
This case provides a very useful review of the authorities as to when a party will be permitted to call his own expert, an order for an SJE notwithstanding. The overall emphasis is that such permission is to be granted if it is fair and just in all the circumstances, which is surely the right test (even if it does not provide much guidance for future cases). Eady J appears to have paid particular attention to the fact that the proposed expert to be called by the claimant was able to give a report setting out a detailed critique of the SJE’s approach. Even though Eady J considered that the proposed expert’s approach might be criticised as “academic” the availability of such a critique appears to have weighed significantly in the balance. That, at least, is useful practical guidance as to how an expert can persuade the court that he should be allowed to provide a report on behalf of a party wishing to call him.
The criticisms based on apparent bias on the part of the SJE (or rather lack of such bias) are also interesting. Eady J had no difficulty dismissing this ground of appeal, and indeed did so in rather summary terms. That is consistent with the robust approach that the courts usually take to allegations of bias, and the very high burden of proof that such applications normally bear. The facts here (which appear to have been simply that the expert had been instructed by the defendants in the past) were not nearly enough to establish bias.
The B submitted that the judge erred in
applying the wrong test when deciding whether the single
joint expert should be disinstructed;
(2) dismissing S's concerns regarding the technical inadequacy of the single joint expert's report and his alleged lack of expertise;
(3) assessing the instant litigation as not being sufficiently "substantial" to justify dispensing with a single joint expert.
(1) In contrast to Kay v West Midlands Strategic Health Authority, the expert evidence in the instant case went to an issue which was far from peripheral, namely the cause of the engine failure. It was fundamental to the resolution of the dispute between the parties and was technical. The judge allowed himself to become too focused on the "exceptionality" test attributed to the judge in Kay, namely whether or not the circumstances were so exceptional as to justify departing from the normal course of appointing a single joint expert, without making sufficient allowance for the fact that, unlike in Kay, the issue in question was not peripheral (see paras 18, 20 of judgment).
(2) S's concerns about the single joint expert's expertise might be proved wrong on closer examination, but B's sense of grievance would be understandable if he had to go through a trial of the critical issue on liability while still being barred from having the relevant points properly investigated (paras 24, 27).
(3) It was impossible to provide a bright line boundary between cases that were "substantial" and those which were not. In any event, whether or not litigation was substantial could not be determined solely by reference to the amount claimed. Issues raised in litigation might be important to the parties or the public generally for a variety of reasons other than financial considerations. The judge thought it appropriate to decide whether it was a "substantial" case, and having decided that it was not, he treated it as a significant factor in refusing B's application. Although it was a relevant factor, it should not have assumed such importance (paras 28-29).
(4) The judge should have allowed S's evidence because it was technical and not peripheral. That was what the overriding objective required, whether the judge assessed the value of B's claim as substantial or not (para.29).