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Rulings on ‘Gatekeeping’ of Expert Testimony

November 20, 2013 in  News

New York Law Journal 

The fact that courts have a prodigious responsibility to carefully screen expert testimony not only for “relevance” but also for “reliability” is beyond question. This task is called “gatekeeping.” If reliable and relevant, the expert’s testimony enters through the admissibility gate. If unreliable, the gate is shut and entry is denied. This judicial screening burden was amply described (and illustrated) in the U.S. Supreme Court’s famous trilogy of decisions in the 1990s—DaubertJoiner and Kumho Tire.1  The Daubert reliability criteria are reflected in Federal Rule of Evidence 702 and the Advisory Committee comments.

This article surveys a potpourri of recent gatekeeping rulings readers may have missed. Lengthy analysis of case facts is omitted. Rather, the pith and substance of the decisions are specified along with interesting insights or glosses that should be noted. The first case in our gatekeeping survey is Dash v. Mayweather, a Sept. 26 decision by the U.S. Court of Appeals for the Fourth Circuit.2  This was a copyright infringement action against the boxing champion, Floyd Mayweather, and others complaining that the song “Yep,” which was played during Mayweather’s entrance at two World Wrestling Entertainment (WWE) events, infringed plaintiff’s copyright in a musical composition called “Tony Gunz Beat” (TGB). Following discovery and a number of stipulations, the South Carolina district court bifurcated liability and damage issues addressing the latter first.

In response to defendants’ motions for partial summary judgment on damages, plaintiff filed a report by an expert, concluding that plaintiff Anthony Dash was entitled to over $1 million in lost profits. The expert came to that figure by calculating the value of Mayweather’s appearance at the events relative to the net profits derived at the events. He then calculated the value of “Yep” to Mayweather’s appearances based on the minutes “Yep” was used relative to the length of Mayweather’s performance. The court held a hearing on the summary judgment motions and then granted them. The district court held that the report estimation of TGB’s market value and lost profits was nothing more than speculation.

On plaintiff’s appeal, the Fourth Circuit affirmed. It detailed the variety of ways a copyrighted work’s market value can be measured. Regardless of the measure used, the copyright holder “must prove the existence of a causal connection between the alleged infringement and some loss of anticipated revenue.” The expert  used four “benchmark license fees paid to other artists for use of their songs at a Wrestlemania event.” The Fourth Circuit deemed such estimation “too speculative.”

Taken as a whole, the expert’s report demonstrated only that (1) certain music plays an important role in professional wrestling matches; (2) the WWE recognizes the value of such music through its operation of an in-house music business; (3) the WWE played a song that included Dash’s now-copyrighted beat at two events, Wrestlemania XXIV and the Aug. 24, 2009, RAW broadcast; (4) the WWE paid four well-established artists licensing fees for use of their recognizable works at Wrestlemania XXIV; and (5) sometime prior to 2011, plaintiff Dash received some recognition (but no compensation) for his work as a musical artist.

The appellate court concluded that it would have to build “inference upon inference” to conclude that these facts were sufficient to stave off defendants’ proof that plaintiff’s works and, especially TGB, do not have a fair market value. The court detailed a variety of ways new artists can establish damages. But here, there was “too great an analytical gap between the [benchmarks] and the opinion offered” to oppose the summary judgment motion. Similar failures in causation proof infected the opinions on lost profit damages. Accordingly, the grant of summary judgment was affirmed.

‘Differential Diagnosis’

In Morritt v. Stryker Corp.,3 plaintiff sued for an allegedly defective polyethylene tibial insert that was a component of the knee prosthesis implanted in plaintiff. Plaintiff’s expert, referred to in the decision only as Dr. Montalbano, was an orthopedic surgeon and plaintiff’s treating physician who submitted a declaration in opposition to defendant’s motion for summary judgment. Montalbano had over a decade of experience using Stryker knee systems. In addition to his normal treatment opinions, however, Montalbano also opined that premature polyethylene wear caused the knee injury and that a manufacturing or material or design defect caused the tibial insert to fail. Defendant moved in limine to preclude Montalbano from opining on issues relating to biomedical engineering and medical device manufacturing. After enumerating applicable gatekeeping reliability standards, the U.S. Magistrate Judge addressed Montalbano’s opinions regarding the alleged product failure.

The court held that Montalbano should not be permitted to offer his opinion regarding the source of the polyethylene wear. Montalbano averred that he performed a “differential diagnosis” which excluded certain alternative causes of the tibial insert failure, i.e., malalignment and bone cement. However, Montalbano’s exclusion of bone cement as an alternative cause went well beyond the “reasonable confines” of his clinical expertise. Indeed, his expertise simply did not extend to manufacturing processes, biomedical engineering, material science and bone cement pathology.

The “differential diagnosis” used by Montalbano also was inadmissible because he failed to employ a reliable scientific methodology to reach such a conclusion. While there may be instances where differential diagnosis is sufficient to support an expert’s causation opinion, here Montalbano did not observe the tibial insert under a microscope after it was removed, did not analyze or test the polyethylene and did not cite to manufacturing records or pertinent scientific literature. His qualifications to reliably exclude certain alternative causes and to “rule in” a manufacturing or material or design defect were lacking.

Additionally, Montalbano’s differential diagnosis relied impermissibly on information learned outside of treatment. Earlier, he was precluded by the court from relying on the reports of Stryker’s experts in his differential diagnosis. That preclusion of certain facts and opinions “casts further doubt on the reliability of his differential diagnosis.” Indeed, at his deposition, Montalbano admitted that he told his patient that he did not have an explanation why the insert failed prematurely. Accordingly, the products liability opinions were precluded. District Court Judge Roslynn R. Mauskopf adopted the magistrate’s report and recommendation “in its entirety.”

Products Liability Claims

In MMG Insurance v. Samsung Electronics,4 a house fire was alleged to have started in a home theater system manufactured by Samsung and sold by Best Buy. The insurance company paid the loss and, via subrogation, brought products liability claims. One of plaintiff’s expert witnesses did certain burn testing which the court excluded upon defendants’ motion. The reason was the failure to show that the testing was performed according to “reliable principles and methods.” Moreover, while the expert’s report referred to testing to determine the voltage and temperature of an exemplar unit’s power supply in different modes of operation, the report made no mention of the expert’s attempts to set fire to various components.

Thus, while plaintiff’s Rule 26(a)(2)(B) disclosure talked about “burn testing,” the actual report did not describe it. An expert’s report must contain “a complete statement of all the opinions the witness will express at trial and the bases and reasons for them.” The report did not comply with Rule 26(a)(2)(B). The fact that the expert had mentioned “burn testing” at his deposition was unavailing.

Rule 26(a)(2) generally “does not allow parties to cure deficient expert reports by supplementing them with later deposition testimony.” Were it otherwise, the function of expert reports would be “completely undermined.” The reason for requiring the expert report to be provided before a deposition is taken is to allow the opposing party to use the report to examine the expert at the deposition. The disclosure failure here was not “harmless.”

Internet Postings. One of the interesting rulings in the MMG Insurance case involved defendant’s motion to prevent plaintiff from referring at trial to other fires caused by similar Samsung products. In litigation parlance such proof is called “other accidents” evidence or “OSI” (“other similar incidents”). This is a common battleground in litigation involving mass-produced products. Such proof can be quite effective yet highly prejudicial. The interesting twist in this case is that the evidence of other fires was in the form of postings on third-party Internet sites. Defendants argued such Internet reports were inadmissible hearsay. They also complained that the postings did not show that the other fires occurred under substantially similar conditions to those in this case. Further, defendants contended that the postings’ prejudicial effect would outweigh any probative value.

In response, plaintiff argued that the postings were not being introduced for the truth of the matter they assert but to impeach defendant’s expert. He relied on Samsung’s data indicating there are no other reports of fire involving the company’s product in reaching his conclusion that the product did not cause the house fire. Additionally, evidence that other such product-caused fires may have existed but that the defense expert’s failure to look into them was a challenge to his credibility.

The court observed that five postings were in controversy. They were submitted to third-party websites such as,, and Although they involved Samsung home theater systems, none of them had the same model number as the system here. The postings failed to identify the circumstances of the alleged fires in any detail. Two simply said the unit “caught fire,” while others offered cursory descriptions of “flames” or “smoke.” Only one of the postings identified its author by a full name. The others were submitted under a first initial and last name, pseudonymously (“SECTOR SE7EN”), or anonymously.

Based on these shortcomings, the court ruled that the web postings were not “creditable information” that could justify cross-examining the defense expert as to his “failure to look into them” in developing his opinion. The court also noted that plaintiff’s expert likewise did not rely on these kinds of materials in concluding the unit caused the fire. Notwithstanding the foregoing, the court observed that Federal Civil Procedure Rule 403 would exclude information “if the danger is too large that the jury will misuse it in damaging ways.”

Here, that danger was substantial relative to the low probative value of the reports. Moreover, defendant would be unable to rebut the inference they would raise because the postings are “effectively anonymous” and describe incidents that occurred several years ago. These factors made it impossible to investigate the reports and develop facts in rebuttal.

‘Warnings’ Expert

In Calisi v. Abbott Laboratories,5 the drug Humira was alleged to have caused plaintiff’s lymphoma. Humira was approved by the FDA to treat moderate to severe rheumatoid arthritis. However, the drug is a “TNF” (tumor necrosis factor) inhibitor, also known as a TNF-blocker drug. Lymphomas have been observed in patients treated with TNF blocking agents including Humira. Plaintiff sued for negligence and breach of warranty. She claimed that Abbott failed to warn her treating rheumatologist about alleged risks of lymphoma from taking Humira.

Abbott moved for summary judgment and to exclude testimony by all four of plaintiff’s experts. One of those was plaintiff’s “warnings” expert, Dr. Michael Hamrell.6 The court granted exclusion of Hamrell’s testimony on warnings. Why? Hamrell concluded that the Humira warning label was inadequate and misleading and proposed an alternative warning that could have been given. Primarily, he deemed the Humira label “incomplete,” particularly regarding general and statistical results of clinical trials. However, the purpose of a label’s information is to allow a medical doctor to make a properly informed decision when prescribing a drug.

Thus, the key issue was whether the alleged accurate-but-incomplete information would be adequate information to such a physician. Hamrell concluded it did not. But did he have a reliable basis for his opinion? Plaintiff had to show that her expert’s opinion on adequacy was not “connected to existing data only by the ipse dixit of the expert.” Hamrell must have had a sufficient basis for understanding what information is needed by a doctor in making his prescribing decision. Plaintiff, however, did not make this showing.

Hamrell was not a medical doctor and did not have qualifications to opine on what is clinically appropriate in treating patients. He was not an expert in psychology, cognitive decision making or behavioral science. Nor did he point to experience-based facts as to how the label’s relevant target audience (medical doctors) would interpret the Humira labels. Based on deposition testimony which the court quoted, it concluded that the expert was not qualified to opine “as to the adequacy for prescribing purposes or confusion that this may generate in the label’s target audience.” Additionally, he would not be qualified to testify as to his proposed alternative label’s impact on prescribing physicians, i.e., whether they would find the information conveyed to be adequate. Interested readers seeking guidance on how to parse a “warnings” expert’s opinions and “Daubertize” them should study the court’s opinion in depth.

Expert Report

In Davis v. Kawasaki Motors,7 a motorcycle suddenly stalled and failed to accelerate. The injured plaintiff sued for defective design and manufacture, claiming that the voltage regulator caused the mishap. An expert submitted his report after the court granted an extension to do so. It was titled “Preliminary Expert Report” but failed to identify any defect in the voltage regulator. Rather, the report stated that work had not been completed and reserved “the right to change [this] opinion if new or further information is presented.” The expert mentioned the results of a test he performed but concluded that the test was inadequate and suggested a second, different test of the regulator that would be done. Defendant filed a motion to strike the report and for summary judgment.

Defendant claimed the report was inadequate since it was “preliminary” in nature. Further, it failed to find a defect in the regulator and proposed additional testing beyond the deadline for filing expert witness reports. Plaintiff responded to the motion but a few days later filed a motion to dismiss the lawsuit. Instead, plaintiff filed a suit against Kawasaki in state court and there added the state Department of Transportation as a party. Defendant opposed the attempt at voluntary dismissal since it would negate a valid defense­—the untimeliness of the expert report.

The federal court refused to dismiss the case, struck the expert’s report as incomplete and granted summary judgment. At the heart of the court’s reasoning is that the rule requiring full expert disclosure is intended to avoid “sketchy and vague” information. Rule 26 “is not designed to permit continuous testing by a party should it be dissatisfied with its prior results.” Plaintiff had adequate time to conduct the tests or to seek additional time for further testing.


The foregoing survey reflects that robust judicial gatekeeping of experts ensues and that counsel on both sides need to exercise diligence in structuring or challenging the reliability of expert testimony and complying with rules on expert disclosure.

Michael Hoenig is a member of Herzfeld & Rubin.


  1.  Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993); General Electric v. Joiner, 522 U.S. 136 (1997);Kumho Tire v. Carmichael, 526 U.S. 137 (1999).
  2.  731 F.3d 303, 2013 U.S. App. LEXIS 19675 (4th Cir. Sept. 26, 2013).
  3.  2013 U.S. Dist. LEXIS 135861 (E.D.N.Y. Sept. 23, 2013) (Judge Roslynn R. Mauskopf), adopting in its entirety the Report and Recommendation of U.S. Magistrate Judge Ramon E. Reyes, Jr., 2013 U.S. Dist. Lexis 136843 (E.D.N.Y. Aug. 12, 2013).
  4.  2013 U.S. Dist. Lexis 79079 (D.N.H. June 5, 2013).
  5.  2013 U.S. Dist. Lexis 139257 (D. Mass. Sept. 27, 2013).
  6.  Hamrell earned a Bachelor of Science degree in Biochemistry and a Ph.D. in Pharmacology. Following a fellowship and other work experience, from 1985 to 1990, he worked at the FDA as a pharmacologist reviewer. Then he worked two years at the National Institutes of Health on all regulatory aspects of a research program for developing AIDS therapies. He has done extensive consulting work including some for Abbott.
  7.  2013 U.S. Dist. Lexis 137507 (S.D.Ga. Sept. 25, 2013).