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The Expert Witness - the filler of gaps
Francis Miller
The role of the expert witness is not usually far away from topical discussion. Procedures and the law about expert evidence are often commented upon at length in the technical press. Headline topics about expert evidence frequently appear in the public media. Stories about miscarriages of justice which have come about because of expert evidence and the despair and anguish caused by it are not uncommon. So, with such a mass of written attention to the topic, why should I add a further contribution; especially, when I have not stepped once into the witness box as an expert? In response to that, I am hoping that when you get to the end of this article you will have a satisfactory answer.
In the same way that a vacuum is liable to be filled unless it is well secured, so a gap in evidence is liable to be occupied by expert evidence. It could also be said that the filling of gaps by expert evidence has something of a magnetic power about it, negative and positive poles seeking each other out. The party with the point to prove, but lacking the necessary evidence, marrying up with the expert who has the tools needed to do the job and who is anxious to have the instruction and to help secure the desired result.
If that desired result is to be the right result in accordance with the law, it is my opinion [humble, not expert] that this inevitable force which binds the party to the expert witness is so powerful that all potential experts should tread the path with caution and reluctance. Further, that this caution and reluctance should be the greater the more that opinion evidence is the key factor demanded from the expert.
In relation to my last sentence, I expect that some readers may say that 'opinion evidence' is what distinguishes an expert witness from an ordinary witness of fact so it is inevitable that the expert witness is bound to be giving opinion evidence. Thus, some readers may conclude that my last sentence is a pointless remark. However, although there would be an obvious truth in such a rebuff, it is the case that expert evidence ranges from simple factual evidence, e.g., test results, to evidence which is almost entirely opinion based, e.g., mental attitudes. Hence my point about the degree, i.e., that the more that opinion evidence is the key factor, the greater the need for caution and reluctance on the part of the expert.
In general, it seems to me that one of the most critical aspects in considering evidence given by an expert witness is about finding the true dividing line between what could be simple evidence of fact and what should be evidence of opinion. Further, sometimes, it seems to me that in many cases the opinion element is often the least important part of the evidence given by the expert. The problem is that often the only person qualified to make these dividing lines clear is the expert. Moreover, the greater the degree of expertise, the greater is the problem for anyone else, save a comparable expert, to understand the matter sufficiently in order to make a realistic judgment about what is opinion and what is fact and, furthermore, about what is the value of the evidence in the context of the topic under consideration.
In support of my observation about the dividing line between what could be simple evidence of fact and what should be evidence of opinion and the relative importance of the latter, I can refer to a frequent situation which occurs in my own industry. In the construction industry, much of the so called expert evidence is little more than a presentation of factual evidence which has been researched by an expert who has been specially engaged to do that research. Indeed, often, when I have listened to so called opinion evidence, I have concluded that the opinion evidence was given simply as an alternative to having to search out the facts. In further support of this and reverting to my opening paragraph, perhaps one of the reasons why I have never found myself in the witness box as an expert is that upon researching the facts for my client, I have in nine cases out of every ten been my own client's worst nightmare. In the other case out of each ten, my client's opponent was alerted to the real case which had to be answered and the matter was settled. Indeed, in nearly every case in which I had been involved, the only expert opinion which I gave was simply explaining to my client about how best to search out the relevant facts and to stress the consequences of a failure to do so. [If some of my past client's read this, perhaps they will say that I am using an author's licence, because the ratio for the nightmare was really ten out of ten! Either way, I don't mind because whenever I was engaged to assist a client, I admit totally to my being obsessed with fact finding. Apposite to this is the fact that sadly we sometimes hear of older experts who have lost the drive to search deep for the facts and who begin to rely upon the Midas touch; with the result that they are often demolished at a time of their life when they should be revered for all the good work which they have done in the past. The only saving from such a fate is to always proceed along the path with great caution.]
In further support of my observation about the dividing line between what could be simple evidence of fact and what should be evidence of opinion and the relative importance of the latter, I refer to the declining value of opinion evidence in some areas, indeed, often the elimination of the value of opinion evidence. In this context, I like to refer to a talk, given in 1977 [dated, but in context still valid], by Mr. J.C.S. Mackie, who was at the time the Director-General of the Grain and Feed Trade Association. In an aside from his written text [reported in Arbitration, October 1977, p. 13], he intimated that parties who were being frustrated in creating disputes out of issues of quality because of the development of scientific analysis were now turning their attention to contractual issues. I regarded this as important because, as I understood it, parties to commodity disputes used to engage experts who argued, based on opinion evidence, for their respective clients that the commodity was either in accordance with the contract or not; according to the position their respective client was taking. However, when scientific experts were able factually to determine compliance with the contract without the need of any added opinion evidence, then the parties turned to lawyers for assistance so that the dispute could be based on an element of the contract which could never be scientifically determined, namely: the the law and the judgment of a court. Things do not seem to change, as one door closes another opens.
At the present time, DNA testing is, of course, yet another step which is helping to eliminate opinion evidence. This is obviously a big step on from Mr Mackie's observation about the modest scientific analysis of commodities some 30 years ago, but it is still on the same theme and one begins to shudder when thinking about the value of much past opinion evidence. Where the gaps in the factual evidence must still be filled by expert opinion evidence, one continues to enter into the real danger zone of potentially unreliable evidence. This danger zone can be more easily highlighted in the criminal law, where a judgment should be based on guilt beyond reasonable doubt. As for my way of thinking, in such a test of guilt, opinion evidence should rarely, if at all, turn the scale toward a conviction because it is evidence which is potentially just a combination of suspicion and opinion; and that can hardly ever match the test of 'beyond reasonable doubt'.
However, I can more easily accept that opinion evidence can be given to help save someone's skin where all the other evidence in the trial begins to get near to the state of being beyond reasonable doubt. By way of a passing remark, in the context of a failure to achieve a conviction under the criminal law, I think that sometimes one has to end up relying upon the aspect which Plutarch considered some two thousand years ago in his essay 'On God's slowness to punish'. If I understand it correctly, he identified the internal mental punishment which wrongdoers often suffer, which suffering is not always perceived by another person. Thus, failure to secure a guilty conviction does not necessarily save someone from the internal punishment which they may suffer; especially those whose aberration is of an isolated nature. Of course, for the hardened criminal the matter may be different, but such criminals inevitably continually present the police with more opportunities for prosecution so the police usually have more than one opportunity for a successful prosecution. This is the situation which one may say is the game-play of the skilled criminal and the skilled policeman at work; the pitting of wits between adversaries; the stuff of movie-making. Fortunately, in most of our work, the burden of proof is 'on the balance of probability'.
On this lower level of burden of proof, it is my opinion, especially for the construction industry, that factual evidence properly researched and properly presented is usually sufficient in most cases, where the claim is justified, to tip the scales on the balance of probability. Perhaps your own experience is different from mine, but I am very much driven toward the concept that fact finding is simply unwelcomed boring hard work which involves many hours of research. Often the solution, in the context of this article, is for the claimant or the defendant to search for the suitable expert as the soft option to full fact finding; or, worse, simply as an attempt to persuade by opinion evidence because the full facts would, if offered, prove unhelpful. I am also driven towards the concept that the great age of opinion evidence is being gradually driven out by a greater realisation by the decision makers that the facts are frequently available where there is a desire to search properly.
In concluding, my point is that the soft option of opinion evidence in lieu of fact finding should always be denied to the client of the expert who wants to do the job properly. Moreover, the offering of opinion evidence because facts are simply not available should be offered cautiously and reluctantly by an expert. Indeed, the expert, as the gap filler, who may tip the scales on the balance of probability in civil cases or beyond reasonable doubt in criminal cases carries a very great burden, especially because the expert may be the only person who really knows the true value of the evidence which has been given. Inevitably, the expert is often both the witness giving the evidence and the only person equipped to judge the merits of the evidence. I wonder how many experts themselves suffer the concept propounded by Plutarch?
Francis Miller