Pursuing Different Constructions Before the PTAB & Court?

Since the PTAB started applying the Philips standard for claim construction, petitioners have put a lot more thought into their proposed claim constructions. This is because it is no longer possible to point to the PTAB’s use of the broadest reasonable interpretation (BRI) as the basis for a different construction.

Now, petitioners are very careful to be consistent with disputed terms.  But, what happens if a petitioner argues for a broader construction at the PTAB, then argues for a more narrowed construction in the district court?

Judicial estoppel comes to mind, an argument explored recently in Panduit Corp. v. Corning Inc., No. 5:18-CV-229-FL (W.D.N.C. July 2, 2021) (here)

In Panduit, a Judge Flanagan in the Eastern District of North Carolina declined to judicially estop Defendant from arguing for a narrowed claim construction of terms that it asserted as having plain meaning before the PTAB (institution denied).

Generally, for judicial estoppel to apply (1) the party to be estopped must be asserting a position that is factually incompatible with a position taken in a prior judicial or administrative proceeding; (2) the prior inconsistent position must have been accepted by the tribunal; and (3) the party to be estopped must have taken inconsistent positions intentionally for the purpose of gaining unfair advantage.

For Plaintiff’s part, it argued that Defendant, should be estopped from arguing claim construction during Markman because arguing anything other than the position taken at the PTAB would be an inconsistent position before the District Court. Defendant, on the other hand, noted in its responsive claim construction brief that the claim terms at issue were not litigated before the PTAB.

Judge Flanagan, citing the generally principles of judicial estoppel, rejected the argument. The Court focused on the third factor of judicial estoppel. In doing so, it concluded that unless the position was chosen to strategically gain an advantage in litigation the Defendant would not be estopped. The judge concluded that Plaintiff failed to show an intent on the part of the defendant, explaining:

[P]laintiff failed to show that defendant engaged in malfeasance, purposefully inequitable conduct, or otherwise intentionally misled this court or the Patent Trial and Appeal Board before which it petitioned for inter partes review of plaintiff’s patents in suit.

Perhaps the change in construction was due to a non-infringement defense irrelevant to the PTAB’s work on invalidity. Often times terms that would otherwise be construed in a district court action for non-infringement purposes are missing from PTAB disputes. Indeed, it is rare to see more than 2-3 disputed constructions (if any) in an average PTAB dispute — not so much on the district court side.

It is worth noting that judicial estoppel is circuit specific, so, your mileage may vary. Of course, while Judge Flanagan found the proposed relief overly harsh, at the very least the defendant was colored as a bad actor.