Author:Butt, Adam Elliott


This Article analyzes the concurrent expert evidence model ("hot tubbing") which has been most strongly promoted in Australia and is increasingly becoming a normalized procedure in other international jurisdictions. The Article asks whether, and to what extent, the model has a useful role to play in toxic harms cases in the U.S. and in civil cases more generally? It answers this question by arguing that concurrent evidence certainly does have a useful role to play in the U.S., for all of the reasons that the model has become a preferred process in Australia. Principally, these reasons are that the model serves to enhance the efficiency and quality of the evidence taking process. The first Part of the Article traverses concurrent evidence's jurisprudential backdrop in Australia, expanding on two useful cases in which the model's benefits have been on display, one being a major toxics case (and Australia's largest ever class action), and the other being a case from another area of complex litigation in which hot tubbing is now a standard process, native title. The second Part of the Article takes this preliminary analysis and concentrates on the U.S. legal context, using toxics as a focal point. The Article argues that hot tubbing would in many instances be a preferable process for adducing and testing expert evidence in U.S. civil cases compared to traditional adversarial methods, both during a pre-trial part of a proceeding, or during the trial itself. The Article also argues that use of hot tubbing in the U.S. is consistent with the letter and spirit of the federal rules of evidence and procedure, but it would be preferable to clarify the acceptability of the process through the adoption of suitable legislative amendments. In making relevant arguments, the Article draws on original views from interviews conducted of senior U.S. and Australian judges, in addition to the views of U.S. and Australian lawyers, experts and academics.

  1. INTRODUCTION II. CONCURRENT EVIDENCE--AUSTRALIA'S MODEL (AND ELSEWHERE) A. Introduction B. Problems with Adversarial Process C. Legislative Frameworks and Benefits D. Kilmore East Bushfires 1. Time Saving 2. Benefits to All Litigation Participants 3. Accuracy 4. Strategic Considerations 5. Suitable Experts and Partisanship 6. Conclusion E. Ngadju 1. Narrowing and Resolving Issues 2. Time Saving 3. Cooperation/Collegiality 4. Interaction 5. Testing the Evidence 6. Partisanship III. HOW HOT TUBBING SITS IN THE AMERICAN CONTEXT A. Areas of Resistance in the U.S. B. Hot Tubbing Under U.S. Federal Legislation 1. FRE 2. FRCP IV. USE OF HOT TUBBING AND SIMILAR CONDUCT IN U.S. TOXICS AND CIVIL CASES A. The Toxics Harms Space and Judicial Responses B. Uses of Hot Tubbing in U.S. Courts 1. Pre-trial Uses 2. Trial Uses V. CONCLUSION APPENDIX 1--AUSTRALIAN LEGISLATION EXAMPLES (3 PROVIDED) APPENDIX 2--KILMORE EAST BUSHFIRES TRANSCRIPT, FORREST J, 25 FEB 2014 APPENDIX 3--EXPERT WITNESS CODES OF CONDUCT (NOW HARMONISED) APPENDIX 4--IN RE XARELTO (RIVAROXABAN) PRODS. LI AB. LIT., SCIENCE DAY ORDER I. INTRODUCTION

    "Hot tubbing" is the colloquial name for a process of adducing and testing expert evidence, which is more formally known as concurrent expert evidence. The model has been championed in Australia (1) and is now used in other common law jurisdictions (2) and in international arbitrations. (3) Its interest and controversy principally lies in the fact that it requires party-appointed experts to engage in cooperative and interactive pre-trial and/or trial endeavors, in order to enhance the efficiency, accuracy and ideally collegiality of the expert evidence process.

    Australia's version of concurrent evidence involves two interrelated processes. First, there is a pre-trial joint expert conferencing (or conclave) phase. During this part, the parties' experts meet for the purpose of clarifying areas of agreement and/or disagreement between them, in order to produce a joint report on such matters. The conference may or may not be conducted with a moderator present, depending on context. The parties' lawyers will normally not be present. The second part of the process, if any, is the giving of concurrent expert evidence at trial. During this phase, the experts will sit together at court in the "hot tub" (e.g. a witness box), and present evidence concurrently in an interactive process which is moderated by the judge. The experts still give their separate opinions and are still cross-examined by counsel as occurs in a traditional adversarial trial. However, in this instance the experts present their viewpoints concurrently instead of sequentially, and there is interaction among the experts should they see a need to "correct" or to "disagree" with each other's views. The judge will also intervene as appropriate with questions in order to enhance the fact-finding process for him or herself. This is a form of "live" learning. The process is intended to be a discussion among professionals which enhances the search for the truth. It embraces a higher level of judicial management and so involves certain inquisitorial features, yet it also maintains fundamentally adversarial techniques albeit in a non-traditional setting.

    This model has been designed to, and does, in general, help to narrow, clarify and resolve issues in dispute with greater efficiency and accuracy across a broad range of subject areas in Australia. According to Justice McClellan, one of concurrent evidence's key proponents in Australia, the process is "one of the most important recent reforms in the civil trial process in Australia." (4) The importance of hot tubbing was on full display in Australia's recent and largest ever class action, Matthews v SPI Electricity Pty Ltd & Ors ("Kilmore East Bushfires"). (5) In that case, concurrent evidence helped to resolve the claims of some 10,500 group members who commenced proceedings in the wake of the 2009 Black Saturday bushfires in Victoria. While the case ultimately settled in December 2014, just before the judgment was handed down, by then all of the expert evidence had been heard, and the vast majority of the evidence had gone through a hot tubbing process. (6)

    Beyond the toxics domain, hot tubbing also yields significant benefits across various other practice areas in Australia, including native title. (7) One particular case, which is less known in academic circles, is the highly illustrative matter of Graham on behalf of the Ngadju People v WA ("Ngadju"). (8) In order to highlight key benefits of the concurrent evidence process, I will assess the use of the model in both Kilmore East Bushfires and Ngadju.

    After providing this introductory analysis, I will proceed to answer the question of whether, and to what extent, hot tubbing has a useful role to play in U.S. toxic harms cases specifically and in civil cases more generally? My answer is that hot tubbing certainly does have a useful role to play in such matters, at several potential stages of a case. These stages include joint expert conferences, depositions, Daubert hearings, summary judgment hearings, class certification hearings, injunction requests, judge-alone trials and potentially jury trials. Concurrent evidence can also help with settlement negotiations.

    United States toxics cases raise similar problems to those which are experienced in Australian matters which ultimately led to the development of the use of concurrent evidence in the first place. Such problems include large litigation costs and inefficiencies, the need to comprehend complex expert evidence, evidentiary reliability concerns and expert bias/partisanship. The U.S. system can and should benefit from processes which have been specifically designed to alleviate such problems, in the same way that jurisdictions across the globe now benefit from such models. It seems somewhat anomalous that the process has taken longer to gain traction in the U.S., which one assumes is attributable to the continued use of civil juries-which have largely been removed in other common law jurisdictions-where the jury, and not the judge, is the fact-finder, in addition to there being some strong adversarial traditions.

    My argument in support of the model traverses several issues which include the following matters. First, I argue that the use of concurrent evidence is consistent with the overarching goals and the general letter of the federal rules of evidence and procedure. That said, the application of concurrent evidence in the U.S. would be enhanced if the rules were amended to reflect and promote the model. Secondly, various practices in the U.S. are emerging to overcome the problems which frequently attend toxics cases (complex evidence, expert partisanship, inefficiencies, etc.), underscoring the need for, and mapping a trajectory towards, the application of hot tubbing in the U.S. These practices include jury consultants, and judges, requiring experts to present evidence "back to back" instead of "sequentially" to improve one's understanding of the evidence, judges holding "science days" in MDL litigation and appointing "expert panels" in pre-trial hearings, in order to similarly improve their comprehension of the evidence, and, perhaps most tellingly, judges now actually using hot tubbing in U.S. trials on occasion, whether of their own initiative or upon the request of the parties. In these instances where hot tubbing, or "hot tubbing like," processes are being used, the feedback about the method is consistently that it was "extremely valuable and enlightening." (9) Thirdly, the type of case-management techniques which are used in concurrent evidence processes are very similar to the nontraditional case management methods which have been successfully employed to efficiently and justly resolve some major U.S. toxics cases. In notable cases such as the 9/11 litigation (involving Judge Heller stein), or the Agent Orange litigation (involving Judge...

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