A Blog About Intellectual Property Litigation and the District of Delaware


Entries for tag: Expert Witness

Court Declines to Move Markman Hearing Based on Expert Conflict, After Warning Parties That They "Should Have [Their] Experts Prepared to Be There."

Andrew E. Russell, Feb. 4, 2026
Expert Witness Scheduling

I never thought we'd get to re-use this image of someone frantically flying from Texas to Delaware (approximately...), but here we are.
I never thought we'd get to re-use this image of someone frantically flying from Texas to Delaware (approximately...), but here we are. AI-Generated, displayed with permission

It's important to pay attention to the things the Court tells you at the scheduling conference.

At a scheduling conference in Koninklijke Philips N.V. v. Quectel Wireless Solutions Co. Ltd., C.A. No. 20-1707-CFC-CJB (D. Del.), back in September, 2025, the Court set a date for the Markman hearing, and emphasized the importance of experts being there:

So let's do the Markman February 10th at 9:00 a.m. Now, I'm telling you now, you should have your experts prepared to be there.

Id., D.I. 141 at 2.

In the lead up to …

View

Court Orders Party to Make Unavailable Expert Witness Available for Deposition on a Better Date, or Face Potential Preclusion

Andrew E. Russell, June 2, 2025
Expert Witness Expert Discovery

Turn Around
Jim Wilson, Unsplash

This is something you don't see often. In Kaneka Corporation v. Designs For Health, Inc., C.A. No. 21-209-WCB (D. Del.), the plaintiff contacted the Court after defendant's counsel offered only a single potential date for the deposition of the defendant's expert, and that date was just five days (and three business days) after the expert's non-infringement report.

The case has been going since 2022, with many twists and turns and amended scheduling orders. One of the most recent scheduling orders set deadlines of May 16 for opening expert reports and May 30 for responsive reports, with the close of expert discovery to close on June 13.

The defendant offered an opening report from …

View

Court Holds That No, You Can't Just Recycle an Expert Opinion from a Prior Case

Andrew E. Russell, May 28, 2025
Expert Witness Expert Discovery

Recycle Bin
Sigmund, Unsplash

We missed an interesting decision from Judge Fallon last month. In Marquinez et al v. Dole Food Company Inc., C.A. No. 12-695-RGA-SRF, D.I. 582 (D. Del. Apr. 24, 2025), Judge Fallon rejected an attempt to "recycle" an expert opinion from a prior, related action.

Apparently the plaintiff had previously retained the experts, and attempted to re-use their prior expert opinions, by admitting the transcript of their prior testimony:

The Hendler Declaration confirms that both witnesses were formally retained as expert witnesses in a prior litigation, they served expert reports in the prior litigation, and both were asked but declined to serve as retained expert witnesses in this case. (D.I. 580 at ¶¶ 9-13) Plaintiffs …
View

Judge Williams Declines to Exclude Expert Opinions on the Law by a Law Professor and a Lawyer (for a Bench Trial)

Andrew E. Russell, Feb. 26, 2025
Expert Witness Expert Discovery

"Your honor, in my expert opinion, the law says we win. Their expert is wrong, because he thinks the law says we lose." AI-Generated, displayed with permission

The Court often excludes experts who offer opinions regarding U.S. law itself—but there are some gray areas and circumstances where the Court has permitted such testimony. In patent cases, for example, the Court has typically excluded expert testimony about substantive issues of patent law, but has sometimes permitted experts to testify on PTO procedures (and sometimes not).

This week we got some more guidance, specifically in the context of a bench trial. In Upsher-Smith Laboratories LLC v. Zydus Pharmaceuticals (USA) Inc., C.A. No. 21-1132-GBW, the Court unsealed an order from last year …

View

The Risks of Deposing the Other Party's Expert

Andrew E. Russell, Nov. 15, 2024
Expert Witness Expert Discovery

Should we take our chances now with a motion to strike, or later with a <a href='#' class='abbreviation' data-bs-toggle='tooltip' data-placement='top' title='Motion in Limine'>MIL</a>? Or just not play?
Should we take our chances now with a motion to strike, or later with a MIL? Or just not play? Hush Naidoo Jade Photography, Unsplash

You don't have to depose the other parties' experts, and strategically, sometimes it can make sense not to. If you have a good sense that their report(s) are flawed and they may use the deposition to try to add key information to the record (regardless of your questions), it may make sense to avoid the deposition altogether.

That strategy is less common but certainly not unheard of—assuming trial counsel is confident in their positioning and ability to …

View

No, You Can't Do That—Court Rejects Attempt to Offer Expert Testimony Regarding Strength of Own Prior Defenses

Andrew E. Russell, Jan. 17, 2024
Expert Witness Expert Testimony

"What do you mean, attorney argument! This is unbiased expert testimony about how awesome our positions are." Braydon Anderson, Unsplash

Well, this is a new one for me. In Wirtgen America, Inc. v. Caterpillar, Inc., C.A. No. 17-770-JDW-MPT (D. Del. Jan. 16, 2024), the plaintiff had previously brought an action in the ITC against the defendant, and won—achieving an exclusion order that stood up (in part) on appeal.

Now, in a District of Delaware action on the same patents, plaintiff argues willfulness based in part on the previous ITC ruling. Defendant tried to offer an expert who would testify about how great its defenses were at the ITC:

Caterpillar offers Mr. Bartkowski to opine on how …
View

Court Clarifies That an Expert Declaration Submitted After Reply Reports Can Serve as a Basis to Expand Expert's Trial Testimony (If You Have the Right Scheduling Order)

Andrew E. Russell, Jan. 5, 2024
Expert Witness Expert Reports

I have no idea what picture would go with this post. Enjoy some nice, royalty-free antelope.
I have no idea what picture would go with this post. Enjoy some nice, royalty-free antelope. NEOM, Unsplash

Years ago, Judge Stark added language to his form scheduling order to resolve a common dispute: can an expert submit a declaration in support of summary judgment?

The language requires the parties to agree in advance, at the start of the case, whether they will permit this:

Expert Report Supplementation. The parties agree they [will] [will not] [CHOOSE ONE] permit expert declarations to be filed in connection with motions briefing (including case-dispositive motions).

Judge Stark has since moved up, but several D. Del. judges still use this language in their scheduling orders, including Judges Noreika, Hall, Burke, and …

View

Throwback Thursday to an Undead Inventor

Emily S. DiBenedetto, May 24, 2023
Expert Witness Pennypack

Today we highlight a decade-old opinion involving an inventor’s death, the reports of which were greatly exaggerated. The moral of the story: trust but verify. Do a Google search, even if you have it on good authority. Question your assumptions.

It's an oddball case that provides the perfect foil for Nate’s article yesterday involving the opposite fact-pattern—a dead expert. Here, an inventor thought expired was “not only alive, but also willing (‘indeed eager’)” to testify in the upcoming trial, scheduled only ten days away.

In an unusual mix-up, plaintiff relied on testimony from the plaintiff’s 30(b)(6) witness, a former high-ranking officer for plaintiff's company, who said that the inventor was deceased. Where'd he get that information? Several of plaintiff’s …

View

No, You Can't Use One Date for a Royalty Calculation and Another for the Hypothetical Negotiation, Without Evidence of Earlier Infringement

Andrew E. Russell, Jan. 5, 2023
Expert Witness Damages

Photograph of a damages expert report involving the Georgia-Pacific factors, the Panduit test, apportionment, convoyed sales, non-infringing alternatives, marking . . .
Photograph of a damages expert report involving the Georgia-Pacific factors, the Panduit test, apportionment, convoyed sales, non-infringing alternatives, marking . . . Luca J, Unsplash

It seems like people are always messing up with patent damages experts. There are just a lot of ways to get tripped up on damages, and—obviously—big incentives to take risks to drive damages numbers up or down.

We had another example of that on Monday, when visiting Judge McCalla granted a Daubert motion and excluded testimony from an expert who applied a later date for the start of infringing sales for the royalty calculation, and an earlier date for the hypothetical negotiation. The expert apparently used a December 2014 date for his royalty calculation:

Wonderland argues that neither Evenflo nor Mr. Peterson presented evidence of any manufacture or testing that occurred at the dates that Mr. Peterson suggested. . . . Wonderland supports its assertion by pointing to sections of Mr. Peterson’s report and deposition in which Mr. Peterson . . . uses December 2014 and not an earlier date as the starting point for calculating royalty damages based on his hypothetical rate. . . .

But the expert used an earlier date for the reasonably royalty calculation, arguing that the earlier date is when the infringement actually began:

When using a hypothetical negotiation to assess damages, “the date of the hypothetical negotiation is the date that the infringement began.” . . . Mr. Peterson asserts that a date falling between December 2013 and April 2, 2014 “more naturally aligns with the actual date of first infringement.” . . .

But the Court found that the party had failed to put forth evidence of the earlier date, and ...

View

Judge Andrews Puts Accused Infringer on Notice that "If It Causes a Mistrial by Poor Preparation or Poor Judgment in Questioning [Certain Witnesses], It Will, at a Minimum, Have to Pay [the Patentee's] Attorney Fees"

Andrew E. Russell, Aug. 22, 2022
Expert Witness Trial

Be Careful
Josh Frenette, Unsplash

In a pair of orders last week in Shopify Inc. v. Express Mobile, Inc., C.A. No. 19-439-RGA (D. Del.), Judge Andrews set out guidelines for the trial testimony of two fact witnesses, who will offer testimony at trial regarding some prior art references (among other things).

The procedural background here is surprising. The patentee moved in limine to exclude the testimony of these witnesses, and the Court addressed the motion at a pre-trial status conference. There, the Court directed that the parties depose the witnesses and that the accused infringer submit proffers of the testimony that will be offered at trial.

That a Lot of Briefing

The parties then filed a stipulation setting …

View
Older

Archive