PLEADINGS, FACTS AND EXPERT EVIDENCE: EXPERT SHOULD NOT “USURP THE FUNCTION OF THE COURT”
There is an interesting discussion of the purpose of pleadings and expert evidence in the judgment of HH Parkes QC in PP -v- The Home Office  EWHC 663 (QB). The fact that an expert report is referred to in the Particulars of Claim does not make the report admissible. Similarly the fact that money has already been spent on a report did not have any impact upon the court’s discretion in relation to the admissibility of the report.
“there is nothing in Professor Piotrowicz’s report that is necessary to assist the court in its task. Moreover, the conclusions of the report usurp the court’s function as the ultimate decision maker. It is therefore not admissible evidence. The fact that the claimant’s advisers have already spent public money on the report cannot alter that consequence. I refuse the claimant permission to rely upon it.”
The judge was deciding three preliminary issues in an action where the claimant was seeking damages – alleging a failure to make reasonable enquiries that she was a victim of human trafficking. One of the issues the court was considering was whether the claimant should be allowed to rely on an expert report.
THE JUDGMENT ON WHETHER THE CLAIMANT SHOULD BE ALLOWED TO RELY ON EXPERT EVIDENCE
RELIANCE ON THE REPORT OF PROFESSOR PIOTROWICZ
The conventional function of pleadings is to plead the facts on which a party relies, not the evidence required to prove them. Unconventionally, then, Mr Buttler pleaded evidence, or at least appended evidence to his Particulars of Claim, in the form of an expert report by Professor Piotrowicz of Aberystwyth University.
The professor is an eminent expert in migration law and particularly in the trafficking of human beings, and he is a member of the Council of Europe’s Group of Experts on Action against Trafficking in Human Beings (GRETA). He offers the opinion that there were reasonable grounds on 19 June 2013 to believe that the claimant might have been trafficked, that the UK authorities (he means the current defendants) should have realised this and referred her case, should have taken steps to provide assistance to the claimant as a person who might reasonably have been believed to have been trafficked, and should have investigated a situation of potential trafficking in accordance with Art.4. Moreover, he concludes that on 19 June 2013 there were sufficient grounds in the account given to the Home Office by the claimant to indicate that she might have been trafficked.
Mr Anderson has referred me to the joint judgment of Lords Reed and Hodge (with whom the other Justices agreed) in the Scots case of Kennedy v Cordia (Services) LLP  UKSC 6;  1 WLR 597.
It is clear from Kennedy at  that four particular considerations govern the admissibility of expert evidence. All four apply both to opinion evidence and to expert evidence of fact, where the expert witness draws on the knowledge and experience of others rather than or in addition to personal observation or its equivalent. In the case of the first consideration, the threshold for admissibility of opinion evidence is necessity. The four considerations are
i) whether the proposed expert evidence will assist the court in its task;
ii) whether the witness has the necessary knowledge and experience;
iii) whether the witness is impartial in his or her presentation and assessment of the evidence; and
iv) whether there is a reliable body of knowledge or experience to underpin the expert’s evidence.
The decision in Kennedy shows that if the subject matter of the expert’s opinion is necessary for the proper resolution of the dispute, and the judge would be unable to reach a sound conclusion without the help of the expert, then expert evidence will be needed. But if the judge can form his own conclusions without help, an expert’s opinion is unnecessary. The expert must avoid usurping the functions of the judge as the ultimate decision maker.
In Professor Piotrowicz’ case, there can be no doubt about his knowledge or experience of trafficking. I do not think that Mr Anderson challenged it, except to the extent of observing that the professor does not have expertise in carrying out or managing the process of assessment and decision as to whether or not to refer.
Mr Anderson submits that expert evidence is simply not necessary: the court is well used to determining issues of the lawfulness of decisions in relation to trafficking, and has done so without the benefit of expert evidence. Secondly, he submits that the issue of whether or not the facts were such that a referral should have been made goes to the very issue that the court has to decide. Thirdly, he questions whether the professor’s opinions can be said to be based on an established body of knowledge concerning the identification of potential victims of trafficking. Finally, he makes the point that costs should not be incurred in calling an expert witness to give unnecessary evidence.
On the question of the necessity of the evidence, Mr Buttler argues that the court will have to determine what standard of care was owed by frontline officers to the claimant and whether the standard reasonably expected of officers was breached in this case, just as would be necessary in a professional negligence claim. The judge cannot decide in a vacuum whether the information available to frontline officials should have triggered further enquiry. The question is whether the conduct of the immigration officer(s) fell below the standard of knowledge and inquiry expected of front line staff.
He also relies on the fact that the drafters of the Anti-Trafficking Convention, which informs the Art.4 duty, expressly recognised a role for experts in the implementation of the Convention. He points to Art.36, which provides for the establishment of a Group of Experts on Action Against Trafficking in Human Beings (‘GRETA’), one of whom is Professor Piotrowicz. The function of GRETA is (inter alia) to advise the Council of Europe on whether member states have properly implemented the Convention. In his skeleton argument he moves seamlessly from that statement of GRETA’s function to the conclusion that the draftsmen of the Convention had (he does not say ‘thereby’, but it is implicit) identified the need for expert opinion in determining compliance with (inter alia) the duty of investigation of potential trafficking. That does not seem to me to follow from the premise, and in any event such generalities are of little assistance on this question.
As for costs, Mr Buttler argues that the costs of the report have already been incurred, and it would be wasteful to throw them away when there is a realistic prospect of the trial judge deriving some assistance from the report. It should not, he suggests, be necessary for the professor to be called to give oral evidence, and the cost of written questions should be modest. In any event, the trial judge can always decide that the evidence does not assist; why, he asks, rule it inadmissible at this stage?
I will assume that the court will have, as Mr Buttler says, to determine the standard of care owed to the claimant by frontline officers. That is a matter on which I can accept that expert evidence could be helpful and admissible, just as it would be if the issue was the standard of care reasonably to be expected of a competent surgeon or accountant.
The difficulty, it seems to me, is that there is absolutely nothing in the report which assists on that question. What the professor does in his report is to set out the facts of the case, state what possible conclusions could be drawn from them, explain the duty to investigate, and state the conclusion that there were reasonable grounds on 19 June 2013 to believe that the claimant might have been trafficked, and that the defendant should have realised this and referred the case for investigation. That is an expression of opinion on the ultimate issue, which is a matter for the court and not for Professor Piotrowicz. I do not suggest that Professor Piotrowicz has approached his task other than in an independent and impartial spirit, but in my judgment the contents of the report, the concluding expression of opinion on the ultimate issue apart, are no more than one would expect from a written argument by competent counsel.
I do not say that expert evidence is not in principle admissible in a case such as this. But in my judgment there is nothing in Professor Piotrowicz’s report that is necessary to assist the court in its task. Moreover, the conclusions of the report usurp the court’s function as the ultimate decision maker. It is therefore not admissible evidence. The fact that the claimant’s advisers have already spent public money on the report cannot alter that consequence. I refuse the claimant permission to rely upon it.
- When is expert evidence admissible? A masterly exposition.
- Judicial assessment of expert evidence.
- An expert displaying zealotry is no help at all (and usually harmful).
- Revisiting Whitehouse -v- Jordan 2: on the lawyers drafting the experts’ reports.
- Expert shopping: changing experts and disclosure of reports.
- The Arroyo Judgment 2: Experts, oh Experts.
- Experts: you’re not right just because you’re famous
- The interchange between lawyers & experts: a difficult issue
- Experts and facts: it is all in the rules.
- The role of the expert witness in litigation: Supreme Court Guidance
- Expert reports: too long and not much use.
- More on experts: non-compliance with the rules taints the evidence badly
- The credibility of witnesses: joint meetings and overreaching experts: a case to point.
- Over eager experts just do not help: they hinder and harm the case of those who call them.
- Beware the expert evidence who “lectures” the court (and tells the judge who to believe).
- Expert evidence about the veracity of witnesses: well, its probably a waste of time.
- An expert must disclose details of professional relationship with a party otherwise the consequences can be dire.
- Irrelevant evidence, inferences and “forgery”: evidential issues in a High Court case.
- Principles of mitigation of loss & the credibility of expert witnesses.
- I didn’t mean it when I signed the joint report: what happens when experts change their minds?
- Expert evidence: the expert’s role: seeing the wood for the trees.
- Cross-examining expert witnesses: hints, tips and links.
- Experts going on a frolic: a family law case where the expert witness was “thoroughly unhelpful”.