Getting Scientific Proof Into Evidence (and keeping it

Transcription

1 Getting Scientific Proof Into Evidence (and keeping it out ) Anthony G. Hopp, Esq. Edwards Wildman Palmer LLP Chicago, Illinois 2011 Edwards Wildman Palmer LLP & Edwards Wildman Palmer UK LLP

2 When are experts necessary? The traditional rule: Expert testimony is necessary when the issue to be resolved is beyond the ken of the average juror The job of an expert is to explain highly technical subjects to a group of people who have no background in the area, often have no interest, have been involuntarily summoned, and were unable to get out of jury duty This group of people will be asked to decide who wins and who loses 2

3 What is the danger posed by experts? By definition, an expert s testimony is not necessary unless the subject is beyond the jurors understanding Both sides will use experts to help convince the jurors to reach opposite conclusions The jury needs to decide which expert s scientific proof is more convincing The danger is that a dishonest or overeager expert will attempt to baffle them with bull 3

4 As a great man once said 4

5 As a practical matter Experts are almost always necessary in environmental and toxic tort cases to help prove: Fate and transport Exposure or dispersion modeling Human exposure and dose Risk Causation Damages State of the art/industry Design or manufacturing defect 5

6 Expert testimony is required When the plaintiff needs scientific evidence to carry his or her burden of proof Examples: Environmental Contamination Property Damage Toxic Injury Failure to disclose an expert in such a case will result in summary judgment. If plaintiffs expert is barred, summary judgment should follow Experts are not optional in cases involving scientific and technical issues as an element of plaintiff's case 6

7 Federal Rules FRCP 702: A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if: (a) the expert s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert has reliably applied the principles and methods to the facts of the case 7

8 Burden of proof In a toxic exposure case, the plaintiff must prove both general and specific causation General Causation: The substance at issue can cause plaintiff s alleged illness at some dose level Specific Causation: The plaintiff s exposure and dose level were sufficient to cause his or her disease If cause and effect were easy to figure out, we would not need experts, or Daubert 8

9 Cases where challenges will be likely Uncommon exposures and common illnesses Common exposures and uncommon illnesses Low level exposures not known to cause illness High level exposures known to cause a different illness Alleged illnesses or associations not yet recognized by medical science The potential for future illness 9

10 Daubert: Focus on Method The purpose the rule in Daubert is to make certain that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field. In other words, Daubert separates expert opinion evidence based on good grounds from subjective speculation that masquerades as scientific knowledge. But Daubert and it progeny do not provide a definitive check list for when expert evidence will be admitted or excluded 10

11 Joiner: Focus on Extrapolation Trained experts commonly extrapolate from existing data. But nothing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence that is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered. Method and results are not always easy to distinguish Joiner suggests that courts can look at the expert s method or the expert s results, i.e. the analytical gap. 11

12 The Analytical Gap 12

13 Post-Daubert and Joiner Hundreds of lower court decisions Each grapples with issues of methodology and results Porter v. Whitehall Laboratories, Inc. The Seventh Circuit affirmed rejection of proposed causation opinions where the witnesses could not distinguish their opinions from mere subjective belief. Even experts must show that they used science and not speculation to come to their conclusions. 13

14 Post-Daubert and Joiner Knight v. Kirby Inland Marine. The Northern District of Mississippi provided a detailed analysis of the Daubert Standard. The Knight court held that an expert must follow a transparent and reproducible method to arrive at a conclusion about general causation. It is important to know whether the theory can and has been tested, whether the known or potential rate of error is acceptable. The Knight court reiterated that science in the courtroom should be no less rigorous than science in the lab. It is not enough to show the data, then hide the analytical method in a black box so that no one can tell how the expert worked through the data to arrive at his ultimate conclusion. If an expert s opinions do not follow a reproducible methodology, then they are nothing more than learned say-so. 14

15 Post-Daubert and Joiner Cavallo v. Star Enterprise. The Eastern District of Virginia excluded opinions from a toxicologist and immunologist, finding that they had failed to explicate what scientific methods they had followed. The toxicologist failed to identify no effect levels for the chemicals he identified as causal agents of plaintiff s respiratory sensitization. The literature upon which he relied did not directly support his conclusions. The immunologist s testimony regarding causation was also excluded because he was unaware of the duration and intensity of the exposure and was unable to support his opinion other by relying on the temporal sequence and some effort to eliminate other possible causes. 15

16 Post-Daubert and Joiner Schmaltz v. Norfolk & Western Ry. Co. The Northern District of Illinois excluded proffered testimony by a treating physician who: (a) was unaware of the level of plaintiff s exposure; (b) knew of no documented cases of defendant s product causing Reactive Airway Dysfunction Syndrome, and; (c) relied on studies of eye irritation in animals rather than respiratory problems in humans. A second expert s opinion was excluded because it was based principally on temporal congruity and not application of scientific analysis. 16

17 So how do you develop admissible proof? Science in the courtroom should be no less rigorous than science in the lab What if there is no lab that studies what you need to prove? You at least need to start with the right expert Think about what you need to prove and find people who work on those issues for a living Get as close as you can 17

18 Sometimes it s easy Environmental fate and transport Air modeling Exposure measurements If you are essentially measuring something, or extrapolating from known data points using generally accepted techniques, the opinions will generally be admissible as long as they are free of errors There are people who do these things for a living, outside the courtroom 18

19 Sometimes it s difficult Dose reconstruction Exposure modeling Risk analysis on a small or individual scale Disease causation If the expert s opinions are not in an area that is routinely practiced outside the courtroom, they should be, and often are, harder to get into evidence 19

20 Keys to admissibility Use an excepted methodology Everything the plaintiff needs to prove has been studied by someone at some time There are accepted methods available Causation: Hill criteria, Koch s postulates Risk analysis: EPA methodology, other published guidance documents Exposure modeling: EPA Chemical Screening Tool For Exposures & Environmental Releases 20

21 Keys to admissibility Follow the methodology you select Obvious departures from the accepted method will cause problems Extrapolation will likely be necessary at some point Be prepared to explain the basis for the extrapolation by reference to outside sources if possible If there is a known error rate, be prepared to address it 21

22 Common fallacies Reasoning from effects to cause Post hoc ergo propter hoc Differential diagnosis by ruling out other causes Undiagnosed genetic susceptibility 30 years of experience 22

23 Common fallacies No methodology or methodology not followed Cherry picking The black box Risk assessment misapplied Exposure assessment based on subjective recollection Cluster analysis based on collective subjective recollection 23

24 Milward v. Acuity Specialty Products Group The substance of an expert s testimony (i.e., did exposure to chemical X cause plaintiff s illness?) should, in theory, be easy to separate from the issue of the admissibility of that testimony (i.e., is the expert s methodology sufficiently robust?) In practice, issues of substance and admissibility often become intertwined The Supreme Court in Joiner observed that conclusions and methodology are not entirely distinct from one another. What happens when an expert s opinion appears to be based on a robust methodology, yet results in a novel, untested or even surprising conclusion? 24

25 Milward v. Acuity Specialty Products Group Plaintiff was a refrigeration technician who claimed that he had contracted Acute Promyelocytic Leukemia ( APL ) from exposure to benzene-containing products manufactured or supplied by defendants. Defendants contended that benzene exposure is not generally accepted to be a cause of APL After a four-day Daubert hearing, the trial court ruled that the plaintiff s expert s causation opinion lacks sufficient demonstrated scientific reliability to warrant its admission under Rule 702. The First Circuit reversed. 25

26 Milward v. Acuity Specialty Products Group The expert claimed to have used a five-step, weight of the evidence methodology, based on the Bradford-Hill criteria The Court recognized that the Hill criteria are not a litmus test Any scientist employing the Hill criteria or any other structured method for evaluating scientific evidence must, in the end, make a judgment as to whether the available evidence supports any inference of causation. The First Circuit held that the trial court had erred by excluding the expert s testimony based primarily on the trial court s finding that the connection between APL and benzene was not generally accepted in the scientific community. 26

27 Milward v. Acuity Specialty Products Group The court s analysis repeatedly challenged the factual underpinnings of [the expert s] opinion, and took sides on questions that are currently the focus of extensive scientific research and debate and on which reasonable scientists can clearly disagree. In this, the court overstepped the authorized bounds of its role as gatekeeper. The soundness of the factual underpinnings of the expert s analysis and the correctness of the expert s conclusions based on that analysis are factual matters to be determined by the trier of fact. When the factual underpinning of an expert s opinion is weak, it is a matter affecting the weight and credibility of the testimony a question to be resolved by the jury. 27

28 Milward v. Acuity Specialty Products Group The Milward case has proved to be extremely controversial. Some commentators contend that Milward has opened the door to the admission of unreliable testimony, as long as the expert can claim to have followed a detailed methodology. One commentator even referred to Milward as the holistic-weightof-the-evidence-via-subjective-judgment-performed-by-anadequately-credentialed-person general causation test. Nonetheless, other courts have begun to follow Milward. 28

29 Mounting A Pre-Trial Daubert Challenge; Factors To Consider Just Because You Can Make A Daubert Challenge Doesn t Mean You Should: Does Your Judge Have A Record In Dealing With Daubert Issues? What Are Your Goals? Pressure Settlement Or Narrow The Issues. 29

30 Daubert Challenges (cont.) Educate The Court As To Your Opponent s Weaknesses. Save Money (by precluding the need for trial testimony from your own experts on certain issues). Land The Knockout Punch (failure of proof because testimony precluded). 30

31 Daubert Challenges (cont.) If Your Challenge Is Unsuccessful, How Much Cross-Examination Ammunition Have You Burned? Have You Just Educated Your Opponent? Cost Are You Better Off Letting The Jury See Their Expert Cross-Examined? 31

32 Timing The Challenge (cont.) If Your Judge s History Suggests It Is Unlikely That He Will Grant A Challenge, You May Want To Wait Until Trial. The Jury May Be Present For The Trial You ll Avoid Educating The Witness In Advance And Giving Him An Opportunity To Better Inform Himself. 32

33 Timing The Challenge (cont.) Waiting For Trial To Make Your Challenge, Besides Potentially Annoying The Judge, Also Prevents Your Judge From Educating Himself On Potentially Complicated Scientific Issues. The Less He Understands, The Less Chance Your Challenge Has. 33

34 How To Deposing The Expert Is It Necessary? Almost always, YES!. However, Exceptions Might Include: Failing To Render The Right Opinion For The Issue At Hand. 34

35 How to (cont.) Reliance On Demonstrably Flawed Science, Studies Or Data. Provable Flaws In Reasoning, Calculations Or Data. Opinions That Tell You Everything He Would Say At A Deposition. 35

36 How To (cont.) You Might Also Not Want To Depose Because: It Gives The Expert A Chance To Educate Himself On The Issues; It May Let The Expert Expand His Theories Beyond What Is In His Report. 36

37 How To (cont.) Important Deposition Pointers Never Accept The Expert s Mere Ipse Dixit (usually in the form of based on my experience ). Probe For Specific Data Relied On To Form Each Opinion. Make Him Cite His Sources With Specificity. Find the Black Box 37

38 How To (cont.) Have The Expert Describe The Scientific Method. Call On Him To Agree That The Scientific Method Is Designed To Produce Reliable Results. Once He Is Locked In, Contrast His Methodology With The Scientific Method. 38

39 How To (cont.) Attack His Peer-Reviewed Credentials. Was The Subject Of His Study Relevant To The Audience That Might Be Expected To Read The Journal. Have Him Identify The Leading Publications, The Ask Why His Study Wasn t Published In One Of Them. 39

40 How To (cont.) Make The Expert Detail His So-Called Experience. Which Experience Did He Rely On? Have Him Outline In Detail Each Step Of His Analytical Process. Have Him Contrast His Methodology With Laboratory Techniques. 40

41 How To (cont.) Require The Expert To Explain Why Contrary Theories Are Wrong Or How They Can Be Explained Away. Call On The Expert To Identify What Tests He Performed. Can He Replicate Results? 41

42 How To (cont.) Be Ever Vigilant For Words Like About, Approximately, I think, Or Any Other Indicia Of Imprecision. This Is Particularly True In Cases Involving The Physical Sciences. 42

43 How To (cont.) Have A Script That, On Key Daubert Points, Requires Yes/No Answers So That, In An MSJ, You Can Give A Summary Of The Text That, In Almost Bullet Like Fashion, Shows What The Expert Did And Did Not Do. 43

44 How To (cont.) Determine The Need For Your Own Experts As Part Of The Challenge. It Is The Methodology Your Experts Will Have To Focus On, Not The Expert s Opinion. And Remember, Live By The Sword, Die By The Sword. 44

45 How To (cont.) Locate Contrary Authority/Studies Valuable (particularly if from an unimpeachable source) Because Expert Can Be Asked To Explain How/Why He Reached A Different Conclusion Or How He Reconciles His Opinion With The Contrary Study. 45

46 How To (cont.) Make Your Challenges Specific, And Tailor Them To The Case. Actively Involve Your Own Expert In Any Challenges (again, live by the sword, die by the sword). Get Affidavits From Other Experts To Support Or Attack The Methodology At Issue. 46

47 How To (cont.) Consider Suggesting To The Court That It Retain Its Own Expert To Assist In Understanding The Science. Usually Reserved For High Profile/Damages Cases, Or Those Involving Extraordinarily Complex Scientific Issues. 47

48 Challenges (cont.) The Most Common Bases For Exclusion: Experts Who Opine Beyond Their Expertise; Opinions Incapable Of Being Verified; Nothing More Than Say So; Unwarranted Assumptions; 48

49 Challenges (cont.) Reliance On Facts That Don t Match The Evidence; Unreliable or Mistaken Data; Gaps Between Opinion And The Data; Not Applying The Same Standard That The Laboratory Would Demand; 49

50 Challenges (cont.) Tests That Fail To Replicate Fully (or accurately) The Relevant Facts: Different model machine; Different weight vehicle; Different type of projectile. 50

51 Hearings Losing A Daubert Motion Can Hurt You, Particularly If There s Time To Cure The Deficiencies. Witnesses can be better prepped. But, When Used Judiciously, Daubert Hearings Can Save Lots Of Money And Maybe Even Win The Case. 51

52 Conclusion Novel scientific theories should be difficult to get into evidence Science should lead the law, not the other way around Many plaintiffs have settled or won based on scientific theories that are later discredited But judges are gatekeepers not triers of fact If your expert strictly follows a transparent, generally accepted method, the evidence should be admissible 52