Even when plaintiffs know of the potential weak spots in their infringement cases, they sometimes fail to address DOE until too late, or they offer a DOE analysis so weak that it gets excluded or wiped out by summary judgment.
That's what happened last week, when Chief Judge Stark struck a DOE opinion after a plaintiff tried to squeak by on the idea that its late DOE argument should be permitted because it never affirmatively declaimed DOE:
Arendi's passing reference to DOE in its complaints followed by its lack of affirmative disclaimer of DOE theories (see, e.g., C.A. No. 12−1595 D.I. 238 at 5) ("Arendi has never asserted that its claims were limited to literal infringement") does not come close to satisfying Arendi's obligation to articulate, in a timely manner, contentions and then expert opinion and linking evidence specifically directed to the claim elements it contends are met (at least contingently) by a theory of equivalents, under the function/way/result and/or insubstantial differences tests . . . . Not even attempting to meet this burden (and, in any event, failing to meet this burden even when it belatedly tried) until a reply expert report is surprising, harmful, and unfairly prejudicial to Google, Motorola, and LG and not substantially justified. Defendants had no opportunity to pursue fact or even expert discovery to counter the new DOE theories, which they might have done by pursuing, for example, different theories of non−infringement, such as ensnarement.
Despite having no trial date set and plenty of time left in the schedule, Chief Judge Stark found that the prejudice to defendant from plaintiff's late DOE disclosure was too great:
While no trial date has been set, and it is possible that further discovery and delay could remedy much of the prejudice, there is no reason to consider such steps, given Arendi's failures with respect to DOE. Arendi's explanation − that Defendants' experts somehow relied on new and improper claim constructions in their non−infringement reports, to which [plaintiff's experts] were entitled to reply − is unpersuasive and unavailing. No expert will be permitted to present an opinion that contradicts the Court's claim constructions; Arendi has not shown this has occurred nor that, if it has, the appropriate relief would be to permit Arendi to expand this case to include DOE theories Arendi was obligated to disclose long ago. The Pennypack factors, as a whole, favor striking.
This continues the trend over the last couple of years towards a more stringent application of the Pennypack factors, where the judges seem a bit more willing to strike or exclude late-disclosed opinions and theories.