The Court of Appeal in Hajigeoriou v Vasiliou [2005] EWCA Civ 236 said that where a party in a civil case has consulted one expert, then chosen to rely on another, it will be usual to order disclosure of the first expert’s report, so as to discourage witness shopping.

The Court of Appeal said almost the same almost two years ago in Beck v Ministry of Defence [2003] EWCA Civ 1043. Mr Beck alleged that negligent treatment by services medical personnel had made his depressive illness worse, so that he could not work. The court said he could not stop the defence instructing a second expert on the ground that a second investigation might be distressing or even slightly dangerous for him. However, they would be required to disclose the report which they did not wish to rely on. The court was unanimous, and the reasoning was that expert shopping is a bad thing.

The same point came up in Hajigeoriou v Vasiliou. First, three arguments against allowing the Defendant to switch from one expert to another were advanced by the Claimant. First, that a party who names an expert then obtains an order permitting him to rely on one expert, cannot change, so as to use someone other than the expert he named when asked for that order. The argument was rejected. Second, that an order permitting a party to rely on one expert did not envisage a succession of experts. The argument was rejected. Third, that changing to a new expert would be unfair because it was unfair to expect the claimant to submit to a second inspection. In this case, it was an inspection of business premises which was in question. Since the it was held reasonable in Beck to expect the Claimant to submit to far more invasive second psychiatric examination, it is not surprising that this argument failed. The court also said that it would not be usual to name a party’s expert in an order allowing that party one expert. The general implication is that no permission is needed to call a particular expert.

On the question of whether, having changed to a second expert, the report of the first expert must be disclosed, the court said it was bound by Beck. Ordinarily the first report, which the party is not going to rely on, must be disclosed. That is to discourage expert witness shopping.

No permission is needed to change one's mind about the identity of one's expert. That in practice disposes of the argument that it is not fair to expect a party to disclose their expert’s report in support of an application to instruct a second argument. The argument is that it is not fair to expect a party applying for a second expert to point out the flaws in their first expert, then perhaps, if they lose the application, have to rely on the expert they have already trashed themselves. In any event, what will happen in most cases now will be an order that a party may rely on a second expert, without first pointing out the problems with their first expert, but they will be able to rely on the second expert only on condition that the first expert’s report is disclosed.

Just how much must be disclosed? The Court said, at paragraph 30, 'A question that was not considered in Beck is whether the condition of disclosure should relate only to the first expert's final report, or whether it should also relate to his or her earlier draft reports. In our view, it should not only apply to the first expert's "final" report, if by that is meant the report signed by the first expert as his or her report for disclosure. It should apply at least to the first expert's report(s) containing the substance of his or her opinion.'

Prosecution disclosure in a criminal case requires the prosecution to disclose any expert evidence which might assist the defence, and that must surely include all unused expert evidence. The disclosure provisions of the Criminal Justice Act 2003, which came into force in April 2005, expressly require unused expert evidence to be disclosed also by the defence (CJA (2003) ss. 33, 35); the disclosure duties on the prosecution cannot be less onerous.

In a criminal case it is now notorious that juries are easily misled by effective experts. Here the American system is much superior to ours.

The damage done by careless, prejudiced, even wacky (though sometimes distinguished) experts is so notorious that it is submitted that it would be unethical for the prosecuting authority or prosecuting counsel to rely on a witness whose is compromised in some undisclosed way, or perhaps even where disclosure is made. Can it be right for the prosecution to call an expert when they know or should know that his or her views or method or qualification or impartiality would not be sufficient to gain the confidence of most of his colleagues? It is not good enough for the prosecution to assume that deficiencies in their expert evidence will be brought home to the jury by the defence. Any prosecutor who takes even a passing interest in legal news knows that a convincing prosecution expert can lead the jury into an error of judgment. A prosecutor who relies on a witness whose evidence is not of the highest quality is obviously risking a miscarriage of justice.

There are some key facts about expert witnesses which tribunals of fact need to know. Judges know them. They are unlikely to be pointed out to a jury. Most expert witnesses are paid more for their testimony than they earn by practicing their profession. Some professionals nevertheless act as expert witness reluctantly, as public service. Others use their expert witness work to enable them to switch to part-time practice of their profession, or give it up entirely, and live very well from their expert fees. Their livelihood is not secure. Their next brief depends on winning cases, or at least doing all an expert can reasonably to do advance their clients’ case. How often are juries told which experts are enjoying a comfortable semi-retirement on their fees, and which can credibly claim they would rather have spent their day in court treating patients, writing up accounts, or doing whatever their primary profession entails?

Career experts who overegg the pudding risk their credibility in civil cases. Judges and lawyers will get to know them and treat them with caution. Not so juries. It may be very difficult for a defence team to demonstrate to a jury that a particular expert deserves a bit of a bad reputation.

The American system, in which experts owe no special duties to the court, is actually healthier the English system. English critics of this aspect of American litigation should remember that along with this attitude, which I regard as a healthy frankness about the realities of expert witnesses, go sensible safeguards. First, in American jury trials the judge is expected routinely to assess the quality of expert evidence before allowing it to go to a jury. The matter has been before the supreme court several times in the past decade. The leading case is Daubert v Merrell Dow Pharmaceuticals. When that rule is properly implemented, it must be a huge disincentive for a party, or a prosecutor, to rely on the kind of woolly-brained experts who continue to contribute to the conviction of the innocent in England.

Second, in many US courts it is the norm, where an expert derives much of his income from his work as a witness, for that expert to be cross-examined on his income, and on how much he makes from his work as an expert witness. A witness can normally also be asked if he usually works for a particular side. To give a hypothetical of example of how that might work in England, if it turns out that Professor Sir Roy Meadows has routinely, or fairly often, acted for a party who argues in favour of keeping children with their parents, then plainly that would say a great deal about him as a man and as medic which a tribunal may wish to take into account when assessing his evidence in one of those cases where the effect of his evidence is to advocate removing children to what is euphemistically called ‘care.’

In the US this caution about the quality of expert evidence has developed gradually and relatively recently. We have followed America in some very damaging ways. Here is one of the many opportunities to borrow something good. In the light of recent problems with expert testimony in the criminal and in family cases in England, a more robust and explicit scepticism about career experts is urgently required here in England, both out of court, before juries, and before judges, in criminal, in family and in civil cases.

Dr John Birchall - Professional English, Legal English, and Common Law Training