Federal Circuit Rejects Patent Attorney Expert Testimony; Finds Patent Obvious

Sundance v. Demonte Fabricating (Fed. Cir. 2008)

Sundance sued Demonte for infringing its patent on a retractable truck tarp. A jury found the patent infringed but obvious. In a post-verdict judgment, the Judge vacated the jury’s obviousness determination – finding the patent not invalid.

Patent Attorney Expert Testimony: On appeal, the Federal Circuit found that the Michigan district court erred by allowing a patent attorney – Dan Bliss – to testify as an expert witness on the issues of infringement and validity on behalf of Demonte. At least some of his testimony focused on issues “exclusively determined from the perspective of ordinary skill in the art” even though he was not qualified as an expert in the art of tarp-making.

“Mr. Bliss is not “qualified as an expert by knowledge, skill, experience, training, or education” in the pertinent art; we therefore fail to see how he could “assist the trier of fact to understand the evidence or to determine a fact in issue.” Fed. R. Evid. 702.


Admitting testimony from a person such as Mr. Bliss, with no skill in the pertinent art, serves only to cause mischief and confuse the factfinder. Unless a patent lawyer is also a qualified technical expert, his testimony on these kinds of technical issues is improper and thus inadmissible.”


We hold that it is an abuse of discretion to permit a witness to testify as an expert on the issues of noninfringement or invalidity unless that witness is qualified as an expert in the pertinent art. Testimony proffered by a witness lacking the relevant technical expertise fails the standard of admissibility under Fed. R. Evid. 702. Indeed, where an issue calls for consideration of evidence from the perspective of one of ordinary skill in the art, it is contradictory to Rule 702 to allow a witness to testify on the issue who is not qualified as a technical expert in that art. We understand that patent lawyers are often qualified to testify as technical experts, but such a qualification must derive from a lawyer’s technical qualifications in the pertinent art.

With Mr. Bliss’s testimony excluded, the Federal Circuit was left with no expert testimony supporting the jury’s obviousness holding. However, following the Supreme Court’s lead in KSR v. Teleflex, the Federal Circuit still felt competent to determine the obviousness on its own. Explaining the appellate court’s competence, the opinion noted that the “technology is simple.”

Holding: Reversed – Claim 1 is invalid as obvious.


  • Way back when: Peggy Focarino was the primary examiner of the patent at issue. Patent No. 5,026,109.