How Patent Owners Should Use Expert Witnesses

Don’t go to the trouble of putting on expert testimony without giving the PTAB basis to rely on it.

Patent Owners use expert witnesses in PTAB proceedings for one basic purpose: to undermine the Petitioner’s case for unpatentability.  Expert witnesses can do this in two ways: by refuting the Petitioner’s evidence, and by introducing new evidence that dilutes the Petitioner’s evidence for unpatentability to less than a preponderance.  In my experience, Patent Owners do too little of the former.  Although witnesses for Patent Owners often contradict Petitioner witnesses, especially as to the meaning of a piece of prior art in the eyes of one of ordinary skill, too often Patent Owner witnesses fail to explain why the Petitioner witness’s analysis is incorrect.  It is not necessarily unreasonable for two experts to disagree on the interpretation of a reference.  The Board often will be forced to look elsewhere in the evidence to reach a disposition if the experts appear simply to be reaching different conclusions without explaining why the opponent’s conclusion is in error.  A better approach is to have the witness show, with specific examples, that an opponent’s witness has based a conclusion on incorrect facts or unwarranted assumptions.  The Board then is armed with a reason to credit one witness’s interpretation over the other’s.