Hop on Pop Redux – Watson Case

Last month, Maxwell Kennerly of the Beasley Firm in Philadelphia posted about the Watson case in his blog.  See Max Kennerly, “The Science And Law Behind The $7 Million Microwave Popcorn Lung Jury Verdict” (Sept. 20, 2012).  This case has attracted a lot of attention, as it well should.  SeeIt’s Alimentary, My Dear Watson” (Sept. 20, 2012); and “Good’s Expert Witness Opinion Not Good Enough in Tenth Circuit” (Sept. 8, 2012).

Kennerly is correct that we should not lump the Watson case with other frivolous cases, such as the infamous McDonald’s hot-coffee spill case.  I suppose people can debate whether McDonald’s sold their coffee at too-high a temperature, but most civilized people can agree that McDonald’s makes bad coffee, and that everyone should be careful what they put between their legs, regardless of temperature.

Watson represents a paradigmatic tort case, involving exposure and diagnostic issues common to many toxic tort cases.  Mr. Watson was a mega-consumer of microwavable popcorn, flavored with diacetyl.  We can assume for discussion that diacetyl can cause bronchiolitis obliterans in factory workers who are exposed at relatively high levels.  There are, however, other causes, as well as idiopathic cases. Two uncertainties overlapped in the Watson case:  diagnosis and exposure assessment.  A treating physician pondered a differential diagnosis between hypersensitivity pneumonitis (HP) and bronchiolitis obliterans (BO).  As a carpet cleaner, Watson had occupational exposures that might well have caused HP.  Indeed, in August 2006, an open lung biopsy requested by his treating physicians, by pathologists at University Hospital, at the University of Colorado, interpreted Watson’s lung pathology as HP.  In 2010, Professor Eugene Mark, a well-known pulmonary pathologist at Harvard Medical School, interpreted the pathology as “in keeping with hypersensitivity pneumonitis.”  Although Dr. Mark was consulting for the defense in this case, he is not a frequent testifier, and his few forays have been almost always for plaintiffs in asbestos cancer cases.  To my understanding, none of the pathologists testified at the trial.

Despite the pathology report, Watson’s treating physician, Dr. Cecile Rose, advocated that the correct diagnosis was BO.  She wrote a letter to NIOSH, and other federal agencies, in which advanced her diagnosis, although she did not mention the hospital pathology.  Regulators and lawyers became involved.  NIOSH measurements of diacetyl in Watson’s home were below the level of detection.  Another set of diacetyl measurements taken by Watson’s legal team reported levels close to that of the industrial workers who sustained BO from workplace exposure to diacetyl.  The plaintiffs’ expert witnesses relied upon these measurements suggesting high exposure.  Just before trial, the defense renewed its Rule 702 motion, challenging the plaintiffs’ exposure level evidence.  The defendant’s motion sought preclusion of the plaintiffs’ expert witnesses’ reliance upon data generated by an Innova Model 1312 Photoacoustic Multi-Gas Monitor.  The court denied this motion, with leave to raise it at trial, and also precluded mention of the testing in front of the jury until the evidentiary matter is resolved. Order of June 22, 2012. I do not know how the court handled this important evidentiary issue at trial, and no analysis of the case is possible until this part of the story is told.

What can be said now, hypothetically, is that if the plaintiffs had no reliable evidence of high exposure, there was precious little in the exposure data to support Watson’s treating physician’s argument for BO, over HP.  The treating clinician did not settle on the BO diagnosis until she had the dubious exposure data. The pathology reports consistently favored the HP diagnosis.

Watson is the third consumer diacetyl case litigated to date.  The Newkirk case resulted in the 702 exclusion of plaintiffs’ expert witness, Dr. Egilman. Newkirk v. ConAgra Foods, Inc., 727 F. Supp. 2d 1006 (E.D.Wash. 2010), aff’d, 438 Fed.Appx. 607 (9th Cir. 2011).  See also Egilman v. ConAgra Foods, Inc., No. 10-35667, U.S. Court of Appeals for the Ninth Circuit (Sept. 5, 2012; unpublished memorandum) (refusing personal appeal of expert witness who claimed defamation and “wrongful exclusion” by district court).  A second case was tried to a jury verdict for the defense, and the appellate court upheld the judgment for the defense.  Khoury v. Conagra Foods, Inc., 368 S.W.3d 189 (Mo. Ct. App. 2012).

Kennerly argues that Watson had proof!  Referring to “evidence” as “proof” is a hyperbolic conceit of lawyers; I am sure have used the expression, as well.  Outside the legal world, proofs and demonstrations are the work of geometers and mathematicians; factual propositions are usually more modestly shown or suggested by evidence.  The “proof” that Kennerly cites is the testimony of Watson’s treating physician, Dr. Cecile Rose, MD, MPH, “a published expert and researcher of occupational pulmonary diseases,” who testified that the basis for her opinion:

“relates mainly to the fact that his lung disease has stabilized with the cessation of use of the product and exposure to the inhalants related with that product. The fact that there was no other causal explanation for his lung condition and the fact that the clinical findings in his lung disease were similar to those that occurred in workers who were exposed to butter flavoring also support that opinion.”

This is the same Dr. Rose who wrote to several federal regulatory agencies, to present a tendentiously abridged clinical case report of a patient with BO, who consumed thousands of bags of microwave diacetyl-flavored popcorn.  Even with the serious omissions of information, and the problematic exposure measurements, Dr. Rose hedged in her attribution:

“It is difficult to make a causal connection based on a single case report. We cannot be sure that this patient’s exposure to butter flavored microwave popcorn from daily heavy preparation has caused his lung disease. However, we have no other plausible explanation. Given the public health implications of this possibility, we wanted to alert you to our concerns.”

To be sure, this is nothing like the McDonald’s coffee-spill case.  This is a case of questioned and questionable science. Kennerly is correct; there is nothing frivolous about the Watson case.  If the diagnosis were correct, and the exposure measurements were accurate, this case would raise very serious public concerns for consumer exposure to diacetyl.  If the antecedents of the BO diagnosis are incorrect, then the judicial system has been snookered, again. The view from over 2,600 kilometers away suggests that the antecedent conditions were unlikely.