Dipak Panigrahy – Expert Witness & Putative Plagiarist

Citing an IARC monograph may be in itself questionable, given the IARC’s deviations from good systematic review practice. Taking the language of an IARC, monograph, and passing it off as your own, without citation or attribution, and leaving out the qualifications and limitations stated in the monograph, should be disqualifying for an expert witness.

And in one federal court, it is.

Last week, on March 18, Senior Judge Roy Bale Dalton, Jr., of Orlando, Florida, granted defendant Lockheed Martin’s Rule 702 motion to exclude the proffered testimony of Dr. Dipak Panigrahy.[1] Panigraphy had opined in his Rule 26 report that seven substances[2] present in the Orlando factory cause eight different types of cancer[3] in 22 of the plaintiffs. Lockheed’s motion asserted that Panigrahy copied IARC verbatim, except for its qualifications and limitations. Judge Dalton reportedly found Panigraphy’s conduct so “blatant that it represents deliberate lack of candor” and an “unreliable methodology.” Although Judge Dalton’s opinion is not yet posted on Westlaw or Google Scholar,[4] the report from Legal Newsline quoted the opinion extensively:

“Here, there is no question that Dr. Panigrahy extensively plagiarized his report… .”

“And his deposition made the plagiarism appear deliberate, as he repeatedly outright refused to acknowledge the long swaths of his report that quote other work verbatim without any quotation marks at all – instead stubbornly insisting that he cited over 1,100 references, as if that resolves the attribution issue (it does not).”

“Indeed, the plagiarism is so ubiquitous throughout the report that it is frankly overwhelming to try to make heads or tails of just what is Dr. Panigrahy’s own work – a task that neither he nor Plaintiffs’ counsel even attempts to tackle.”

There is a wide-range of questionable research practices and dubious inferences that lead to the exclusion of expert witnesses under Rule 702, but I would have thought that Panigraphy was the first witness to have been excluded for plagiarism. Judge Dalton did, however, cite cases involving plagiarism by expert witnesses.[5] Although plagiarism might be framed as a credibility issue, the extent of the plagiarism by Panigraphy represented such an egregious lack of candor that it may justify exclusion under Rule 702.

Judge Dalton’s gatekeeping analysis, however, did not stop with the finding of blatant plagiarism from the IARC monograph. Panigraphy’s report was further methodologically marred by reliance upon the IARC, and his confusion of the IARC hazard evaluation with the required determination of causation in the law of torts. Judge Dalton explained that

“the plagiarism here reflects even deeper methodological problems because the report lifts a great deal of its analysis from IARC in particular. As the Court discussed in the interim causation Order, research agencies like IARC are, understandably, focused on protecting public health and recommending protective standards, rather than evaluating causation from an expert standpoint in the litigation context. IARC determines qualitatively whether substances are carcinogenic to humans; its descriptors have “no quantitative significance” such as more likely than not. Troublingly, Dr. Panigrahy did not grasp this crucial distinction between IARC’s classifications and the general causation preponderance standard. Because so much of Dr. Panigrahy’s report is merely a wholesale adoption of IARC’s findings under the guise of his own expertise, and IARC’s findings in and of themselves are insufficient, he fails to reliably establish general causation.”[6]

Dr. Panigraphy was accepted into medical school at the age of 17. His accelerated education may have left him without a firm understanding of the ethical requirements of scholarship.

Earlier this month, Senior Judge Dalton excluded another expert witness’s opinion testimony, from Dr. Donald Mattison, on autism, multiple sclerosis, and Parkinson’s disease, but permitted opinions on the causation of various birth defects.[7] Judge Dalton’s decisions arise from a group of companion cases, brought by more than 60 claimants against Lockheed Martin for various health conditions alleged to have been caused by Lockheed’s supposed contamination of the air, soil, and groundwater, with chemicals from its weapons manufacturing plant.

The unreliability of Panigraphy’s report led to the entry of summary judgment against the 22 plaintiffs, whose cases turned on the Panigraphy report.

The putative plagiarist, Dr. Panigraphy, is an assistant professor of pathology, at Harvard Medical School, in the department of pathology, Beth Israel Deaconess Medical Center, in Boston.  “The Expert Institute” has a profile of Panigraphy, with a compilation of background information and litigation activities. His opinions were excluded in the federal multi-district litigation concerning Zantac/ranitidine.[8]  Very similar opinions were permitted over defense challenges, in a short, perfunctory order, even shorter on reasoning, in the valsartan multi-district litigation.[9]


[1] John O’Brien, “‘A mess’: Expert in Florida toxic tort plagiarizes cancer research of others, tries to submit it to court,” Legal News Line (Mar. 25, 2024).

[2] trichloroethylene, tetrachloroethylene, formaldehyde, arsenic, hexavalent chromium, trichloroethylene, and styrene.

[3] cancers of the kidney, breast, thyroid, pancreas, liver and bile duct, testicles, and anus, as well as Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, and leukemia.

[4] Henderson v. Lockheed Martin Corp., case no. 6:21-cv-1363-RBD-DCI, document 399 (M.D. Fla. Mar. 18, 2024) (Dalton, S.J.).

[5] Henderson Order at 6, citing Moore v. BASF Corp., No. CIV.A. 11-1001, 2012 WL 6002831, at *7 (E.D. La. Nov. 30, 2012) (excluding expert testimony from Bhaskar Kura), aff’d, 547 F. App’x 513 (5th Cir. 2013); Spiral Direct, Inc. v. Basic Sports Apparel, Inc., No. 6:15-cv-641, 2017 WL 11457208, at *2 (M.D. Fla. Apr. 13, 2017); 293 F. Supp. 3d 1334, 1363 n. 20 (2017); Legier & Materne v. Great Plains Software, Inc., No. CIV.A. 03-0278, 2005 WL 2037346, at *4 (E.D. La. Aug. 3, 2005) (denying motion to exclude proffered testimony because expert witness plagiarized a paragraph in his report).

[6] Henderson Order at 8 -10 (internal citations omitted), citing McClain v. Metabolife Internat’l, Inc., 401 F.3d 1233, 1249 (11th Cir. 2005) (distinguishing agency assessment of risk from judicial assessment of causation); Williams v. Mosaic Fertilizer, LLC, 889 F.3d 1239, 1247 (11th Cir. 2018) (identifying “methodological perils” in relying extensively on regulatory agencies’ precautionary standards to determine causation); Allen v. Pennsylvania Eng’g Corp., 102 F.3d 194, 198 (5th Cir. 1996) (noting that IARC’s “threshold of proof is reasonably lower than that appropriate in tort law, which traditionally makes more particularized inquiries into cause and effect and requires a plaintiff to prove that it is more likely than not that another individual has caused him or her harm”); In re Roundup Prods. Liab. Litig., 390 F. Supp. 3d 1102, 1109 (N.D. Cal. 2018) (“IARC classification is insufficient to get the plaintiffs over the general causation hurdle.”), aff’d, 997 F.3d 941 (9th Cir. 2021).

[7] John O’Brien, “Autism plaintiffs rejected from Florida Lockheed Martin toxic tort,” Legal Newsline (Mar. 15, 2024).

[8][8] In re Zantac (ranitidine) Prods. Liab. Litig., MDL NO. 2924 20-MD-2924, 644 F. Supp. 3d 1075, 1100 (S.D. Fla. 2022).

[9] In re Valsartan, Losartan, and Irbesartan Prods. Liab. Litig., Case 1:19-md-02875-RBK-SAK, document 1958 (D.N.J. Mar. 4, 2022).