Lay Witness Opinion Testimony on Ultimate Question of Obviousness Is Inadmissible at Trial

By Payal Majumdar, Ph.D., and Peter Schechter


In HVLPO2, LLC v. Oxygen Frog, LLC,[1] the U.S. Court of Appeals for the Federal Circuit (“CAFC”) held that a trial court abused its discretion by admitting lay (i.e., non-expert) witness opinion testimony regarding the ultimate question of obviousness during a jury trial.  Such lay witness opinion testimony is unduly prejudicial and circumvents extensive discovery rules and procedures designed to ensure that such opinions are relevant, reliable, and offered by persons qualified to offer them.

HVLPO2, LLC (“HVO”) sued Oxygen Frog and its CEO, Scott Fleischman (collectively, Oxygen Frog) in the U.S. District Court for the Northern District of Florida for infringement of U.S. Patent Nos. 8,876,941 and 9,372,488, claiming oxygen generation circuits.  The patented oxygen-generating system is used to sustain and manage airflow for torch glass artists who use surface mix glass torches. At trial, Oxygen Frog argued that the claims were obvious in view of a combination of two prior art references.  Further, Oxygen Frog introduced testimony of a lay witness, the author of one of the references, on the ultimate question of obviousness to be answered by the jury.  The author of the prior art witness was neither offered, previously identified, nor qualified as an expert in accordance with court rules and procedures for such qualification.  The author did, however, provide deposition testimony as a fact witness during the discovery period of the litigation.  Specifically, the lay witness was asked, “Did you think that modifying the [prior art] system to support two circuits to be obvious?” The witness answered, “Yes.”  HVO objected to the testimony regarding obviousness as improper expert opinion testimony.

The district court overruled HVO’s objection and instead gave the jury a limiting instruction prior to playing the videotaped deposition testimony of the witness. The district court also instructed the jury that it was ultimately up to them to decide the issue of obviousness.  The jury concluded that claims 1 and 7 of both the ’941 and ’488 patents, the only claims at issue in the trial, would have been obvious under 35 U.S.C. § 103. After the jury verdict, HVO moved for judgment as a matter of law that Oxygen Frog had failed to establish obviousness, or in the alternative, for a new trial based on the improper and prejudicial admission of lay opinion testimony on the ultimate issue of obviousness. The district court denied HVO’s motion, and HVO appealed.

The CAFC rejected Oxygen Frog’s argument that allowing the jury to hear the prior art author’s testimony was harmless.  The court noted that Federal Rule of Evidence (“FRE”) 702 provides that “[a] witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if: (a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; . . .”  Oxygen Frog had made no attempt to demonstrate that the lay witness was “qualified as an expert” in accordance with FRE 702 or the case law regarding its application.  Generally speaking, FRE 702 is applied much more rigorously in cases tried to juries than in “bench trials” conducted before district judges without juries.

In addition, the CAFC found that, under the circumstances, the district court’s limiting instruction was insufficient to cure the substantial prejudice caused by the jury listening to and watching the videotaped testimony of the witness. The court explained that such admission of the testimony into evidence deprived HVO of its right to have the obviousness question decided on the basis of admissible, qualified expert testimony, and further prejudiced HVO by circumventing the expert discovery rules that ensure the reliability and relevance of such testimony.  While recognizing that it may be possible for a district court to cure inadmissible testimony by instructing the jury to disregard it, the CAFC held that the district court improperly permitted the jury to consider lay witness testimony as evidence of obviousness in this case.  As is sometimes said, it was not possible to “un-ring the bell” – in other words, there was no way that jurors could reasonably separate the improper testimony from the other properly admitted evidence when deliberating and reaching their verdict.

Thus, the district court was held to have abused its discretion by denying a motion for a new trial.  Quoting an earlier decision on the same point, the CAFC stated that “it is an abuse of discretion to permit a witness to testify as an expert on the issues of non-infringement or invalidity unless that witness is qualified as an expert in the pertinent art.”[2]  The court explained that the prohibition of unqualified lay witness opinion testimony extends to the ultimate conclusions of infringement and validity as well as to the underlying technical questions. A witness not qualified in the pertinent art may not testify as an expert on an obviousness rejection under 35 U.S.C. § 103, or any of the underlying technical questions, such as the nature of the claimed invention, the scope and content of the prior art, the differences between the claimed invention and the prior art, or the motivation of one of ordinary skill in the art to combine these references to achieve the claimed invention.

Regarding the discovery process, the CAFC noted that Oxygen Frog did not disclose the witness as an expert witness in accordance with the Federal Rules of Civil Procedure (“FRCP”), the district court’s local rules, or the scheduling order in the case, nor did the witness submit an expert report providing the bases of his opinion and supporting materials pursuant to FRCP 26(a)(2)(A) and 26(a)(2)(B). The FRE and FRCP carefully govern discovery and trial use of expert testimony, requiring (among other things) that experts be disclosed to the opposing party along with a written report which contains all opinions of the expert, the reasons and bases for those opinions, and all facts relied upon in the formation of the opinion, at the pretrial discovery stage of the litigation.  HVO was not provided with any of the required disclosures concerning the lay witness resulting in substantial prejudice to HVO’s ability to investigate and prepare for the opinion testimony.

The author of a prior art document may be the most qualified person to express an opinion about obviousness or other issues of invalidity or non-infringement.  This case serves as a clear reminder, however, that litigants must comply with all discovery and court procedures and rules regarding identification, qualification, and disclosure of experts and the opinions they will offer at trial.  A jury verdict obtained by “ambush” will not stand, even if the trial judge mistakenly allows the lay witness, who may actually be an “undisclosed expert,” to offer opinion testimony on the issues of non-infringement, invalidity, or any of the underlying technical questions.

[1] 949 F.3d 685 (Fed. Cir. 2020).

[2] Sundance, Inc. v. DeMonte Fabricating Ltd., 550 F.3d 1356, 1363 (Fed. Cir. 2008)