Contention interrogatory responses are a frequent topic of dispute. In theory, using damages as an example, the way it works is this:
- Defendant, who does not have the burden, sends a contention interrogatory.
- Plaintiff provides contentions.
- Defendant takes discovery based on the contentions.
- Plaintiff provides expert reports that fairly elaborate on the contentions.
- Defendant responds using the discovery it took based on the contentions.
- Plaintiff offers expert testimony at trial that is a fair elaboration on their reports.
- Defendant moves to strike any testimony that goes beyond the reports.
The process can get hung up on step 2, however, because parties may try to short-circuit the process and avoid giving away or getting nailed down on contentions early. That way they can wait to disclose their positions until expert discovery, when they know all of the facts. Of course, at that point it will also be harder (or impossible) for the other side to develop responsive facts or positions.
Judge Kennelly Holds That Parties Can Wait Until Expert Reports
Historically, District of Delaware cases typically say that parties must respond to contention interrogatories, and can't defer until the expert report stage. There is, however, at least one recent case going the other way, which I've seen attorneys rely on to refuse a contention interrogatory response:
Scorpcast did not provide a substantive answer [to a contention interrogatory on damages]. Rather it stated that the interrogatories called for expert opinion and that it would provide an answer when it produced its Rule 26(a)(2) expert disclosures regarding damages [i.e., its expert report]. In its response to the motion [to compel] Scorpcast says that it has no further responsive information to provide at this time and that it will supplement its answers after it completes the depositions of several MG Freesites witnesses. That is a sufficient response at this point.
MG Freesites Ltd. v. Scorpcast, LLC, C.A. No. 20-1012-MFK, C.A. No. 21-887-MFK, D.I. 305 (D. Del. Mar. 13, 2023) (Kennelly, J.) (denying motion to compel validity, indirect infringement, and damages contention interrogatory responses).
I've been watching to see what happens if a party tries to rely on that case with another D. Del. judge, but I haven't seen it reach a judge's written order or opinion yet (although if you've seen it come up in a hearing, please let me know, and we may do a follow-up post).
Judge Fallon Holds that Parties Can (Sometimes) Wait Until After a Final Claim Construction Decision
As of this week, we have a second order along similar lines. Judge Fallon denied a motion to compel, and held that a party can hold off on responding to a contention interrogatory until after claim construction—if the answer depends on claim construction:
Plaintiffs' motion to compel Defendant to supplement its response to Interrogatory No. 20 to provide a narrative factual basis and evidence of non-infringement is DENIED without prejudice to renew following the issuance of a final decision on claim construction. Defendant responded to the contention interrogatory with a 10-page list of 198 claim terms that are allegedly not satisfied by the accused products, but it did not include a narrative response or citations to evidence in support. . . . Plaintiffs do not dispute Defendant's position that a further response to Interrogatory No. 20 would turn on disputed issues of claim construction. Courts have held that a contention interrogatory may be premature if it implicates issues of claim construction before the terms have been construed. See ROY-G-BIV Corp. v. Fanuc Ltd., 2008 WL 11346476, at *6 (E.D. Tex. July 15, 2008) (citing Jacobs Chuck Mfg. Co. v. Shandong Weida Mach., C.A. No. 2:05-185, D.I. 93 at 2 (E.D. Tex. Aug. 18, 2006)).
Cerebrum Sensor Technologies, Inc. et al v. Revvo Technologies, Inc., C.A. No. 24-245-JLH-SRF (D. Del. Feb. 5, 2025).
This ruling is not as stringent as Judge Kennelly's. It holds that a contention interrogatory "may" be premature if it implicates claim construction issues. But it could have a significant effect, assuming the other judges follow it.
Obviously, most contention interrogatories in a patent case are going to depend, to at least some extent, on claim construction. And claim construction sometimes occurs on the later side, after the close of fact discovery or even after expert reports (in which case the experts generally offer opinions in the alternative that account for both proposed constructions).
As such, the practical effect in some cases could be that the contention interrogatory responses are not really due until after expert reports. And once expert reports are out, it may not be necessary to supplement at all given that FRCP 26(e) only requires supplementation "if the additional or corrective information has not otherwise been made known"—e.g., in a detailed expert report.
Do two cases make a trend? Is the law evolving away from requiring contention interrogatory responses? I'm guessing no. But I think it's helpful to be aware of the cases either way.
Could We Use a New Local Rule?
It also occurs to me that this could be a place where a new local rule could help, potentially settling the seeming disagreement among precedent. Maybe something like:
RULE 33.1. Contention Interrogatories
Parties may serve contention interrogatories. A responding party may not delay their response to an interrogatory on the basis that it seeks disclosure of contentions. Responses to contention interrogatories regarding issues on which the responding party does not bear the burden of proof shall be due 30 days from the date on which the party bearing the burden of proof discloses its corresponding contentions.
Just an idea. I know others have been working hard towards a local rules update.
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