Reflections following the publication of the RICS Surveyors Acting as Expert Witnesses (5th Edition)
Following my previous articles considering transparency in the use of Expert Witness assistants and the importance of maintaining independence, the publication of the RICS Surveyors Acting as Expert Witnesses (5th Edition) provides an appropriate opportunity to reflect upon another aspect of expert evidence which, in my view, is frequently misunderstood. Whilst much is written about an expert’s overriding duty to the Court or Tribunal, considerably less attention is given to the practical question of how that independence is maintained throughout what may be months, or even years, of involvement in a dispute. Independence is often spoken of as though it were a characteristic that an expert either possesses or lacks. I respectfully suggest that the position is considerably more nuanced. Independence is not simply a state of mind; it is demonstrated by the conduct of the expert throughout the entirety of their appointment.
The principles themselves are, of course, well established. The duties articulated by Cresswell J in National Justice Compania Naviera SA v Prudential Assurance Co Ltd (The Ikarian Reefer) [1993] 2 Lloyd’s Rep 68, subsequently reflected in CPR Part 35, the Civil Justice Council Guidance for the Instruction of Experts in Civil Claims and reinforced within both the RICS Practice Statement and the newly published 5th Edition, make clear that an Expert Witness owes an overriding duty to assist the Court or Tribunal. That duty is owed irrespective of the identity of the instructing party and overrides any obligation owed to the client responsible for the expert’s fees. Few experienced experts would disagree with those principles. The more interesting question, however, is whether merely understanding those duties is sufficient to ensure that genuine independence is preserved throughout an instruction.
In my experience, the answer is almost certainly no. The greatest threat to an expert’s independence is rarely dishonesty or a conscious decision to become partisan. Rather, it is the gradual and often imperceptible effect of prolonged exposure to one party’s narrative. By the time an expert is instructed, the parties have usually developed firmly held views regarding liability, causation and quantum. The expert will attend conferences with solicitors and counsel, review witness statements, examine pleadings, consider disclosure and become immersed in the factual and technical issues giving rise to the dispute. None of those activities is improper. Indeed, they are often essential if the expert is to understand the issues upon which they are required to express an opinion. The difficulty is that repeated exposure to one version of events can, entirely subconsciously, begin to influence the expert’s thinking.
This phenomenon is neither new nor unique to expert evidence. Behavioural psychologists have long recognised the existence of confirmation bias, namely the tendency to attach greater weight to information supporting an emerging conclusion whilst giving less attention to material pointing in another direction. Experts are not immune from that tendency merely because they possess technical expertise or many years of professional experience. On the contrary, experience can occasionally reinforce confidence in an initial assessment, making it all the more important that experts consciously continue to test their own reasoning against the available evidence rather than assuming their provisional conclusions remain correct.
One particularly interesting observation following publication of my previous article came from fellow Expert Witness Gill Hunt, who referred to Richard Moorhead‘s concept of the “professional imaginarium.” It is an expression that immediately resonated with me because it encapsulates a subtle but important risk facing every experienced professional. As surveyors, engineers, architects or accountants, we naturally accumulate a wealth of professional knowledge that enables us to recognise patterns, identify likely causes and anticipate how projects ordinarily evolve. That experience is invaluable. However, there is an important distinction between using professional experience to interpret evidence and allowing professional experience to replace evidence. Tribunals are concerned with what actually occurred, not what usually occurs on projects of a similar nature. An expert must therefore remain alert to the possibility that assumptions founded upon experience may unintentionally fill evidential gaps which ought instead to be investigated.
It is perhaps for this reason that both the Civil Justice Council Guidance and the RICS Practice Statement place such emphasis upon the expert’s investigative role. Holne and Mullen observe that the modern Expert Witness is expected to investigate, not merely accept the information placed before them.
The days of experts simply expressing opinions upon the documents selected by those instructing them, without undertaking their own independent forensic investigation, have long since passed. That observation reflects the realities of modern expert evidence. The expert is expected to identify missing documentation, distinguish assumptions from established fact, consider evidence that may undermine their provisional conclusions and explain, transparently, the reasoning process leading to their final opinion. Those disciplines are not intended to question an expert’s integrity. Rather, they provide the practical safeguards through which independence is continually demonstrated.
My own experience has increasingly reinforced that conclusion. Having acted as an Expert Witness, Single Joint Expert, mediator and adjudicator, together with reviewing the work of other construction professionals in professional negligence claims, I have come to appreciate that genuine independence requires continual discipline rather than simple good intentions.
Interestingly, the shortcomings encountered rarely concern technical competence. More often they arise from process. Assumptions are accepted without sufficient investigation. Alternative explanations are not explored. Documents inconsistent with the expert’s conclusions receive only cursory consideration. Conclusions occasionally appear to have preceded the analysis rather than emerging from it. None of those matters necessarily suggests a lack of integrity. They do, however, raise legitimate questions regarding the robustness of the expert’s reasoning and, ultimately, the confidence that can properly be placed in their conclusions.
Those experiences have also influenced the manner in which I approach my own appointments. I consciously look for documents that may undermine my provisional opinion rather than merely reinforce it. I ask myself what additional documentation ought reasonably to exist and why it has not been disclosed. I revisit my assumptions whenever significant new evidence emerges and regularly consider whether I would express precisely the same opinion had I been instructed by the opposing party and provided with the identical body of evidence. Those questions do not eliminate the possibility of unconscious bias. I believe, however, that they provide an important discipline which assists in maintaining the degree of objectivity expected of every Expert Witness.
Against that background, I do not regard the publication of the RICS 5th Edition as suggesting that experts have become less trustworthy or less ethical than their predecessors. Rather, I see it as recognising the increasing complexity of modern dispute resolution and reinforcing the professional disciplines required to preserve confidence in expert evidence. Independence cannot simply be asserted by reproducing the declaration required at the conclusion of an expert report. It must be evident from the manner in which the expert has investigated the issues, analysed the evidence and reasoned their conclusions.
Ultimately, the most persuasive Expert Witnesses are seldom those who express the strongest opinions or adopt the most emphatic language. They are those whose reports demonstrate intellectual curiosity, analytical rigour and a willingness to challenge their own assumptions as readily as those of others. Independence is not established because an expert believes themselves to be independent. It is earned through conduct. In that respect, I believe the publication of the RICS Surveyors Acting as Expert Witnesses (5th Edition) serves as a timely reminder that the credibility of expert evidence depends not only upon the opinion ultimately expressed, but upon the process by which that opinion has been reached.
I would be genuinely interested to hear the views of fellow Expert Witnesses, adjudicators, arbitrators, mediators, solicitors and barristers.
Do you consider that the greatest threat to an expert’s independence lies in conscious advocacy, or is unconscious confirmation bias the more significant challenge facing the profession today?
I accept appointments as an Expert Witness in relation to quantum, valuation, contractual disputes and professional negligence claims involving Quantity Surveyors, Contract Administrators and Employer’s Agents.