This article was originally published in the EWI's Expert Matters Memeber Magazine.
In this article, Dr Kay Linnell OBE talks about the role of the expert witness, and the problems that can be encountered when Instructing Parties go too far to prevent any accusation of bias or undue influence on appointed party’s expert, risking the expert’s ability to fully assist the Tribunal.
The impartiality and independence of Expert Witnesses giving evidence to Courts, Tribunals and other formal Hearings is crucial to enable them to comply with the well-established overriding obligation to assist the Court or Tribunal by giving an expert understanding of a technical matter on which the Expert is qualified to opine and give guidance using up to date technical material and industry knowledge.
The reason that expert opinion testimony is allowed is to provide clarity on a technical issue not known to those sitting in a judicial capacity to enable them to form an opinion and deliver judgement on the material issues referred to them to determine.
The tests for an individual to be accepted as an expert are well recorded and known from the clear summary in the Re Ikarian Reefer case cited by Sir Peter Cresswell [1993] (2 Lloyd’s Rep 68, 81- 82; [1993] F.S.R. 563; [1993] 37 E.G. 158; Times, March 5, 1993) and further developed through subsequent cases.
Every expert has a professional obligation to stay up to date with developments in their accepted expertise, not to stray outside their expertise or opine on the material issues for the Court or Tribunal. In addition the Expert once instructed should not become a “creature” of the legal team or the litigant instructing them but effectively be able to give their opinion evidence solely to enlighten the Tribunal and without bias, so actually it should not matter which Party instructed the Expert, their evidence on the mattes referred to them should be the same.
Traditionally in the system for instructing experts in England and Wales the instructing solicitor obtains consent from the Court or Tribunal for expert evidence and instructs an expert on those issues. If a single joint expert is used then instructions agreeing the matters to be referred to the expert are agreed between the parties. Both parties then provides a joint letter of instruction and a bundle of all the relevant documents. The Expert then conducts their review and analysis and prepares their report in the prescribed format. The expert must restrict the expert report solely to the matters referred to them only after conducting proper investigations and analysis for the expert to form and state their own independent opinion. The expert report is then served in the proceedings as evidence in chief of the expert and its admissibility is contingent on permission of the Tribunal. Once this has been finalised and served then the expert will answer questions on the report in accordance with Court or Tribunal Protocols
After the report is served the Expert remains under a continuing overriding duty to the Tribunal to update his or her opinion if new facts or information comes to hand that materially alters any conclusion in the written report. In these circumstances the Expert usually prepares a supplementary report but if the information is too late for that to be accommodated in the trial timetable then a verbal update must be given in oral evidence before the Tribunal. There is a continuing duty on the instructing party to update the Expert with any such developments or documents.
When new evidence is presented to the Expert this must be considered in the light of the previous opinion stated in the Expert report whilst maintaining impartiality and independence and remembering the Expert’s overriding duty is to the Tribunal and not the instructing party. Judges have highlighted instances where Experts are unwilling to fairly consider additional evidence and by unreasonably excluding it they are in danger of presenting themselves as an advocate for the instructing party or as a demonstration of bias which undermines their credibility as an Expert witness. Conversely, judges have also commented favourably about Experts who have clearly considered additional evidence and are open to making reasonable concessions and changing their opinion.
If faced with complex additional evidence, the Expert should directly or through instructing solicitors ask the Court to provide adequate time to consider that evidence fully before providing their response. If the Expert decides to change his or her opinion, then the Instructing Party should be told by the Expert as soon as possible.
This process assumes that the Expert will be informed as part of a Party’s litigation team or as a Single Joint Expert by both sets of lawyers for the Parties of any material and relevant developments or changes to available data or valuation matrices. Failure to be kept up to date with new evidence and other relevant developments will undermine the credibility of the Expert under cross examination and in giving oral evidence.
This assumption is being challenged by some recent litigation cases concerning the interpretation of Expert bias, which is the subject of this article. The case of Patricia Andrews & Others v Kronospan Ltd [07.03.22] is a stark reminder of what can go wrong when expert witnesses do not fully understand their duties, in particular overriding duty to the Court, and where lawyers overstep the limits of their roles when instructing them. It is a stark reminder that expert evidence can be excluded, have permission revoked or carry no weight in a trial or hearing.
The case of Jones v Kaney [2011] UKSC 13 removed the immunity protection of Experts giving evidence where their negligence has caused a loss to their client. Many experts feel justifiably concerned at the removal of their immunity, and the result has been that expert opinions and views are now less trenchant at the outset of a case than previously.
In certain other jurisdictions things have gone further and lawyers will act to try to prevent any accusation of bias or undue influence on appointed party’s Experts but this is at a cost to the ability of the Expert to fully assist the Tribunal. I have had personal experience in both India and Canada of being excluded from any contact with my instructing lawyers or clients during the course of hearings which meant I was not aware of new evidence and events and as a direct consequence was severely disadvantaged in cross examination and in updating my opinion. Obviously details of these cases is confidential but I wanted to share this traumatic experience as an Expert because, in my opinion, this fettered my ability and obligation to take account of new evidence that I had not seen until my cross-examination and hampered me in my overriding duty to assist the Tribunal on relevant technical matters.
To understand this more fully it is worth considering the general concepts in Ontario, Canada and Canada generally concerning privilege and admissibility of Expert evidence and to give an overview for witnesses giving evidence internationally. There are some fundamental questions that need to be addressed. I have included three case extracts from the Canadian Courts under the headings below so the reader can evaluate the questions raised themselves.
Litigation Privilege between Expert and Lawyer in Ontario, Canada (from the Ontario Court of Appeal – the highest court in Ontario which is below the Supreme Court of Canada. It is likely that this case would be generally similar in Canada)
In Moore v. Getahun, 2015 ONCA 55 (CA) at paragraph 70 the Court of Appeal held that litigation privilege continued to apply to communication between a lawyer and the expert. In paragraph 64, the Court held that this communication served the useful purpose of helping the expert clarify the report and make it understandable and appropriate. This privilege applies even when the party serves the report and calls the expert to testify. However, the Court stated in paragraphs 77 to 78 that if the party seeking disclosure can show “reasonable grounds to suspect that counsel communicated with an expert witness in a manner likely to interfere with the expert witness’ duties of independence and objectivity,” the court may order disclosure of such communications.
In Carmen Alfano Family Trust v Piersanti, 2012 ONCA 297, para 108, the Court addressed this kind of issue by observing that, “It is not helpful to a court to have an expert simply parrot the position of the retaining client. Courts require more… The fundamental principle in cases involving qualifications of experts is that the expert, although retained by the clients, assists the court.” In other words, an expert who is an advocate for the side that hired him or her does not provide the right kind of assistance.
Admissibility of Expert Testimony in Canada (from the Supreme Court of Canada – the highest court in Canada)
From White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23 (CanLII), [2015] 2 SCR 182:
[23] At the first step, the proponent of the evidence (note: referring to expert evidence) must establish the threshold requirements of admissibility. These are the four Mohan factors (relevance, necessity, absence of an exclusionary rule and a properly qualified expert) and in addition, in the case of an opinion based on novel or contested science or science used for a novel purpose, the reliability of the underlying science for that purpose: J.-L.J., at paras. 33, 35-36 and 47; Trochym, at para. 27; Lederman, Bryant and Fuerst, at pp. 788-89 and 800-801. Relevance at this threshold stage refers to logical relevance: Abbey (ONCA), at para. 82; J.-L.J., at para. 47. Evidence that does not meet these threshold requirements should be excluded. Note that I would retain necessity as a threshold requirement…
[24] At the second discretionary gatekeeping step, the judge balances the potential risks and benefits of admitting the evidence in order to decide whether the potential benefits justify the risks. The required balancing exercise has been described in various ways. In Mohan, Sopinka J. spoke of the “reliability versus effect factor” (p. 21), while in J.-L.J., Binnie J. spoke about “relevance, reliability and necessity” being “measured against the counterweights of consumption of time, prejudice and confusion”: para. 47. Doherty J.A. summed it up well in Abbey, stating that the “trial judge must decide whether expert evidence that meets the preconditions to admissibility is sufficiently beneficial to the trial process to warrant its admission despite the potential harm to the trial process that may flow from the admission of the expert evidence”: para. 76.
Commenting on Credibility of the Parties by an Expert (Ontario, Canada but likely applicable in Canada generally)
“B exceeded his role as an expert when he opined on the credibility and reliability of the parties, indicating that he believed the defendants and not the mother. There was a risk that the members of the jury would accept B's credibility and reliability assessments rather than assess the evidence of the witnesses and reach their own conclusion. Further, the expression of an opinion as to the credibility of witnesses was a breach of B's duty as an expert to be independent.” (from: Rathan et al. v Scheufler et al., 2023 ONSC 3232 (the Ontario Court of Appeal)
My personal experience was that although I was a party expert I was excluded from the room of my instructing client and his legal team and they insisted on getting permission from the Tribunal to even allow me to sit in to hear proceedings on my own in a corner at the back of the hearing room. I was instructed not to speak with any of the parties or their legal teams. However the equivalent expert for the other party was treated as part of his legal team and asked to advise them on documents and technical questions. This inevitably not only made me feel excluded but also gave the other party a tactical advantage and turned the examination of experts into an uneven exercise.
I am convinced the disparity in the treatment of experts caused a loss of credibility and diminished the weight given to my evidence as I was handed documents without any prior notice that were relevant and caused me to revise my opinion whilst on the witness stand without any opportunity to fully consider the full documents or context as the items shown to me were cherry-picked by the cross examining legal team. I did ask for an adjournment but the set timetable agreed between the parties did not allow for such a delay.
You can imagine that my instructing party and their legal team were unhappy with my evidence, when I consider the imbalance was caused by their interpretation of the ‘bias’ case law which was not mirrored by the other legal team. Inevitably I felt that the difficulties caused were not of my making. In the circumstances when I was refused time to consider the documents properly so I addressed the Arbitration panel directly and explained what I had been shown and that there might be other relevant documents that I also had not seen. The Arbitrators accepted that I had been put in an “impossible position” and declined to deal with the quantum parts of the claim at that hearing deferring quantum to a later hearing, which preserved my credibility. My instructing client was not content with this outcome as it increased his costs in the resolution of the dispute. I was not content either as I felt that I could not rely on the instructing party’s legal team to ensure I was kept up to date with all relevant documents and developments.
My view of these case extracts are that the Expert should be responsible to maintain their own expert technical knowledge and independence and not be sent into purdah by the instructing lawyers where Experts are put out of the room to wait to be called. This leads to Experts not being consulted during the course of litigation, key documents and evidence not being requested, obtained or made available to them and being left to be ambushed in cross-examination.
I may be wrong but exclusion of party experts in particular is a very dangerous legal practice and can cost the party their case. The Expert becomes isolated, ill-informed, excluded from proceedings and a target for ‘shock disclosure’ during giving evidence.