The Reference Manual for Scientific Evidence (3rd Ed.) (“RMSE Third”), published by the Federal Judicial Center and the National Research Council of the National Academies,  is an indispensable tool that can support defense lawyers’ efforts  in making their Daubert  motions persuasive.  Contrary to the suggestion made in a recent article appearing in the DRI publication, The Voice (2/21/18), that RMSE Third is “an overlooked litigator’s tool”, it should be consulted not just when crafting Daubert arguments, but in preparing to take plaintiff’s expert’s deposition as well.  In summary, RMSE Third provides a roadmap for handling most, if not all, of the complex technical and scientific issues in your matters.  You overlook RMSE Third at your peril.

The Manual is a unique resource in that federal judges and magistrates often refer to the Manual to help them better understand and evaluate the relevance, reliability and usefulness of the evidence being proffered.  It is frequently cited as authoritative in judicial opinions.  Notably, the Manual’s “Reference Guide on Economic Damages” was cited by the late Justice Antonin Scalia in his majority opinion in Comcast Corporation v. Behrend  (Sup Ct 2013),  the landmark decision on class action jurisprudence.

Some practitioners have expressed concern that that RMSE Third takes a less demanding approach to Daubert than the preceding edition.  For example, concern has been expressed about the reasoning employed by the First Circuit in its  decision in Milward v. Acuity Specialty Products Group, Inc., 693 F.3d 11 (1st Cir. 2011), cited in RMSE Third, which some lawyers believe is contrary to established Supreme Court precedent requiring that expert testimony be admitted only when it is based on sound science.

 Milward involved a plaintiff who alleged that his Acute Promyelocytic Leukemia (“APL”), an extremely rare disease, was caused by his exposure to benzene. The key issue on appeal was whether the expert opinion of plaintiff’s toxicology expert, Dr. Martyn Smith, was admissible on the issue of general causation.  In reversing the district court, which had excluded Dr. Smith’s testimony, the First Circuit held that the district court had erred in treating the separate evidentiary components to Dr. Smith’s analysis “atomistically” in “reasoning that because no line of evidence supported a reliable inference of causation, an inference of causation based on the totality of evidence was unreliable.” The First Circuit concluded that Dr. Smith’s “weight of the evidence” approach was acceptable because Dr. Smith reasoned, “to the best explanation for all of the available evidence.”

To some legal scholars, Milward is unfaithful to prior Daubert precedent for three basic reasons. First, its application of the “weight of the evidence” methodology permits an expert’s opinion to be admitted solely on the basis of the ipse dixit of the expert – i.e., a statement that rests solely on the authority of the expert who made the statement. This is expressly contrary to Joiner, which cautioned that the ipse dixit of the expert does not transform the expert’s opinion into a reliable methodology. Second, reasoning to “the best explanation for all of the evidence available” is not alone sufficient because an expert’s opinion must be excluded when the underlying scientific data do not permit a conclusion beyond hypothesis or speculation. Finally, third,  the First Circuit was wrong to criticize the district court for “atomistically” or, separately, reviewing each evidentiary component of Dr. Smith’s analysis.  An “atomistic” approach is a “holistic” or “aggregate” approach.  In contrast, other Daubert courts have examined each piece of scientific evidence (i.e. each scientific paper) individually rather than in the aggregate.  However, RMSE Third takes a nuanced approach to its discussion of Milward.  The Manual recognizes that in cases of extremely rare diseases, such as APL, it may be difficult to establish “statistically significant” results because the disease occurs so infrequently. Thus, the rationale for the First Circuit’s holding.

RMSE Third frames the issue of “atomization” by asking, “When there is a Daubert challenge to an expert, should the court look to all the studies on which the expert relies for their collective effect or should the court examine the reliability of each study independently?” For its part,  RMSE Third suggests that the former approach may be the more appropriate.  Some legal scholars take issue with this approach.   Although the “weight of the evidence” approach may be used by regulatory agencies to assess the risk of chemicals, that does not render this approach reliable and relevant under Daubert.  It is well known that regulatory agencies will often err on the side of caution without clear scientific evidence, but that Daubert requires that testing and validation occur before evidence is admissible in court.

The first take-away for defense counsel is that RMSE Third is a starting point for legal argument, not the end point.  It may be necessary to distinguish and parse the case cited in the Manual during oral argument.  Milward went up to the First Circuit a second time during the pendency of the case.  In Milward v. Rust-Oleum Corp.,  820 F.3d 469 (April 25, 2016), the First Circuit affirmed the trial court’s granting of summary judgment to the defendant.  In particular, the First Circuit agreed that the trial court was correct in excluding the opinions of plaintiff’s specific causation expert, Sheila Butler, holding:

“The district court also rejected Dr. Butler’s “differential diagnosis.” Although the judge did not question Dr. Butler’s decision to “rule out” obesity and smoking as causes of Brian Milward’s APL, the court was concerned about the utility of the approach given the high percentage of APL cases that are idiopathic (according to the record, roughly 70-80% of all APL diagnoses). The judge also stated that Dr. Butler’s reasoning was circular; she “ruled out” an idiopathic APL by “ruling in” benzene as a cause, but she had failed to provide a scientifically reliable method of “ruling in” benzene in the first instance. The Milwards contend that in making this decision, the district court ignored our case law that has blessed an expert’s use of a differential diagnosis to establish causation.

Thus, given a second chance to toss out a flimsy plaintiff’s case on Daubert grounds, the First Circuit affirmed the trial court’s exclusion of the plaintiff’s specific causation expert. This ruling came down nearly five years after rendering its first decision in the case in which it reversed the trial court’s exclusion of plaintiff’s general causation expert.  The second take-away for defense counsel is that Daubert rulings in complex scientific cases with multiple expert witnesses on both sides often favor the plaintiff on some issues and the defendant on others.  Sometimes, it takes multiple rounds of in limine proceedings to achieve the desired end result, i.e., dismissal!