Magistrate Judge Burke Excludes Expert Testimony

November 11, 2015

Publication| Intellectual Property


In W.L. Gore and Assoc., Inc. v. C.R. Bard, Inc., C.A. No. 11-515-LPS-CJB (Oct. 23, 2015), Magistrate Judge Burke considered defendants’ motion to exclude certain opinions of plaintiff’s damages expert on the grounds that the expert’s opinion on a reasonable royalty rate was based on a conversation that she had with plaintiffs’ technical expert on infringement. Plaintiff’s damages expert opined that the parties would have come to a 15 percent royalty rate had they negotiated for a license of the patents-in-suit. In arriving at this conclusion, the expert used a previously negotiated royalty rate for a patent (the “Goldfarb patent”) that had a “high degree of comparability” to the patents-in-suit. In her deposition, plaintiff’s damages expert stated that the basis for her conclusion that the Goldfarb patent was similar to the patents-in-suit was a conversation that she had with plaintiff’s technical expert. Defendants argued that because the technical expert had not provided an opinion as to the similarity between the Goldfarb patent and the patents-in-suit in his expert report or deposition, it was improper for the damages expert to base her opinion on the conversation she had with the technical expert on these similarities.

In considering the admissibility of the expert’s opinion, Judge Burke began by stating that there must be a showing that the technology at issue in the Goldfarb patent is “sufficiently comparable to the technology at issue in the asserted patents.” Judge Burke stated that, while normally it is acceptable for a damages expert to rely on opinions by a technical expert when performing a damages analysis, the technical expert must be subject to examination on the basis for the opinion that the damages expert relied upon. Judge Burke found that it would not be possible for the technical expert to testify concerning the similarities between the Goldfarb patent and the patents-in-suit because the technical expert had made “only the briefest of reference to the Goldfarb patent in his expert reports.” By testifying about what the technical expert told her in a conversation, the damages expert’s testimony would amount to “the transmission of hearsay to the jury, which is not permissible.”

In fashioning the appropriate remedy, Judge Burke determined that it would not be equitable to exclude the testimony altogether. Rather, Judge Burke found that the testimony “is critical to [plaintiff’s] damages case” and it would not be prejudicial for plaintiff’s technical expert to supplement his report regarding the similarities between the Goldfarb patent and the patents-in-suit. Judge Burke noted that the technical expert was well known to defendants, and the deposition of the damages expert has already given defendants “some sense as to what [the technical expert] would say on the topic.” Accordingly, Judge Burke allowed plaintiff’s technical expert to file an addendum to his expert report to establish a “discernible link” between the Goldfarb patent and the patents-in-suit.


Judge Burke’s decision highlights the difficulty of obtaining complete exclusion of expert testimony in the District of Delaware. Judges will often balance the prejudice involved to determine the appropriate remedy.

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