The U.S. Court of Appeals for the Federal Circuit recently drew a line between permitted testimony by technical experts and prohibited testimony on ultimate issues of patent law by legal experts. The Court held that patent lawyers lacking technical expertise in the pertinent art are not qualified to testify on such technical issues as invalidity and infringement. Sundance, Inc. v. DeMonte Fabricating Ltd., Case Nos. 08-1068, -1115, 2008 U.S. App. LEXIS 26082 (Fed. Cir. Dec. 24, 2008) (Moore, J.).

Sundance sued DeMonte Fabricating Ltd. (DeMonte) for infringement of a patent for retractable covers that are customarily used on trucks. Over Sundance’s objection, the district court allowed a patent lawyer to testify as DeMonte’s expert witness on invalidity and non-infringement. At trial, DeMonte’s patent lawyer offered technical testimony on the claimed invention and prior art and concluded that Sundance’s patent was invalid as obvious. DeMonte’s patent lawyer, however, had no technical experience in the field of the invention and had practiced engineering for less than two years. The case was tried to a jury, and the jury agreed with DeMonte’s patent lawyer on obviousness and invalidity. The district court subsequently overturned the jury’s verdict, granting Sundance’s motion for judgment as a matter of law that the patent-in-suit was valid.

The Federal Circuit reversed, concluding that Sundance’s patent was invalid as obvious-not on the basis of DeMonte’s expert patent law testimony-but as a matter of law. The Court reasoned that expert testimony was not needed in this case because the “technology is simple and neither party claims that expert testimony is required to support such a holding.”

The Court further held that the district court abused its discretion by allowing DeMonte’s patent lawyer, who lacked relevant technical expertise, to testify as an expert witness on the issues of validity and infringement. The Court’s reasoning was simple: DeMonte’s patent lawyer had no technical expertise in the pertinent art and thus could not provide reliable testimony from the perspective of a person of ordinary skill in the art. Such testimony would violate the standard of admissibility under Daubert and Rule 702 of the Federal Rules of Evidence. The Court further reasoned that technical testimony by unqualified patent lawyers “serves only to cause mischief and confuse the factfinder” and “amounts to nothing more than advocacy from the witness stand.” 

DeMonte argued that the Court’s precedent in Snellman v. Ricoh Co., permits patent lawyers to opine on ultimate legal questions of validity and infringement. The Court disagreed with DeMonte’s characterization of Snellman, explaining that such testimony “invades the province of the jury to find facts and that of the court to make ultimate legal conclusions.”

The Court cautioned that its decision should not be read as requiring expert witnesses “to possess something more than ordinary skill in the art.” In addition, the Court noted that those patent lawyers lacking technical expertise in the pertinent art may still testify as expert witnesses “in contexts other than non-infringement and invalidity, such as patent office practice and procedure.”