Written by Chris Walton, JDThe plaintiff in a trade-secret misappropriation case offered six expert witnesses. The defendant moved to exclude all of them under the amended Rule 702. Three were excluded for lack of qualifications or unreliable methodology. A fourth was excluded for failure to comply with disclosure requirements. Two survived. The case produced the most granular application of the amended Rule 702 to a multi-expert roster in the current pipeline — a stress test that shows, expert by expert, what passes and what fails.
In Wolff v. Tomahawk Manufacturing (2025), Judge Michael H. Simon evaluated each expert against the amended Rule 702’s requirements and reached different results for each. The excluded experts failed for distinct reasons: one relied on simple arithmetic and unsupported assumptions rather than accepted valuation methodology, another lacked familiarity with the Georgia-Pacific factors that govern reasonable royalty analysis in trade-secret cases, and an engineering expert failed to provide testing or data to substantiate his conclusions. The admitted experts survived because they offered testable, industry-grounded methods and satisfied the court’s evidentiary requirements.
For litigation counsel assembling an expert team for a trade-secret or IP damages case, Wolff is a case-by-case tutorial in the amended Rule 702’s requirements — and a warning that the amendment’s gatekeeping function can thin your expert roster before trial begins.
The court evaluated each expert independently. The outcomes:
Elisabeth Wolff — excluded. Wolff offered a damages opinion based on simple arithmetic and unsupported assumptions. The court found that her methodology did not constitute the “reliable principles and methods” Rule 702 requires. A damages calculation based on multiplication and subtraction is not, by itself, a methodology — it’s arithmetic applied to assumptions that themselves must be grounded in evidence and accepted analytical frameworks. Without that grounding, the calculation is only as reliable as the assumptions, and the assumptions lacked sufficient support.
This is the same failure mode that sank the expert in BBK v. Central Coast Agriculture (where unsupported disgorgement assumptions were excluded) and the but-for expense methodology in the same case (where hypothetical expense assumptions lacked adequate support). The principle: arithmetic is a tool, not a methodology. The methodology is the analytical framework that produces the inputs. If the framework is missing, the arithmetic is meaningless.
Langston Murray — excluded. Murray offered opinions on damages but lacked familiarity with the Georgia-Pacific factors — the fifteen-factor framework that governs reasonable royalty analysis in patent and trade-secret cases. The Georgia-Pacific factors (from Georgia-Pacific Corp. v. United States Plywood Corp., 318 F. Supp. 1116 (S.D.N.Y. 1970)) are the standard analytical framework for determining a reasonable royalty in IP cases. An expert who offers a royalty opinion without demonstrating familiarity with the framework is offering an opinion without the domain-specific methodology the subject matter requires.
This echoes the credential failure in Sullivan v. Loden, where the expert lacked the specific qualifications to value closely held businesses for gift-tax purposes. The amended Rule 702 demands that the expert’s qualifications match the analytical task. Offering a reasonable royalty opinion without knowing the Georgia-Pacific factors is like offering a DCF opinion without knowing what a discount rate is — the methodology requires the framework, and the framework requires the expertise.
Samuel Gannon — excluded. Gannon was an engineering expert who offered technical conclusions about the trade secrets at issue but failed to provide testing or data to substantiate those conclusions. Under the amended Rule 702, expert opinions must be based on “sufficient facts or data” and must “reliably apply” the expert’s principles and methods to the facts of the case. An engineering opinion that asserts a conclusion without testing, measurement, or data to support it fails both requirements. The conclusion may be correct, but without the evidentiary foundation, the court cannot evaluate its reliability.
Compare this to Matter of Weber, where the expert used Copilot to cross-check calculations but couldn’t explain the inputs, sources, or methodology. Both Gannon and the Weber expert reached conclusions they couldn’t support with transparent, verifiable evidence. The mechanism was different (no testing vs. unreliable AI), but the failure mode was the same: an opinion the court cannot independently evaluate.
Dr. Mith Leng — excluded (procedural). Dr. Leng was excluded not for methodological reasons but for failure to comply with the court’s Trial Management Order and Rule 26 disclosure requirements. Expert reports that are not timely disclosed, that fail to satisfy Rule 26(a)(2)(B)’s requirements, or that violate the court’s scheduling order can be excluded regardless of their substantive quality. This is the same procedural vulnerability that partially sank the plaintiff’s expert in BBK (where the reasonable royalty analysis relied on an undisclosed license agreement). Substance doesn’t matter if the disclosure requirements aren’t met.
Charles Sweat — admitted. Sweat offered expert testimony that the court found met the amended Rule 702’s requirements. His methodology was testable and industry-grounded. The distinction between Sweat and the excluded experts was not that Sweat’s conclusions were more favorable or his credentials more impressive. It was that his analytical approach was transparent, his methods were accepted in the relevant field, and his opinions were based on sufficient facts and data that the court could evaluate.
Dr. Brian Kearns — admitted. Dr. Kearns similarly survived the Daubert challenge because his methodology satisfied the amended Rule 702’s requirements. The court found his opinions were the product of reliable principles and methods reliably applied to the facts of the case.
The contrast between the admitted and excluded experts is instructive. All six were presumably qualified professionals. The three who were excluded failed not because they lacked general expertise but because their specific opinions didn’t satisfy the amended Rule 702’s requirements: Wolff’s arithmetic lacked an analytical framework, Murray didn’t know the applicable legal framework, and Gannon didn’t provide the testing his engineering conclusions required. The two who survived demonstrated that their specific methods were accepted, their specific data was sufficient, and their specific application of method to facts was reliable.
Murray’s exclusion for unfamiliarity with the Georgia-Pacific factors deserves additional attention because it addresses a failure mode specific to IP and trade-secret damages. The Georgia-Pacific factors are the standard framework for determining a reasonable royalty in cases where the plaintiff’s damages are measured by what the parties would have agreed to in a hypothetical negotiation for a license to the IP at issue. The fifteen factors include the royalties the patentee or trade-secret holder has received for licensing the IP, the rates paid by licensees for comparable IP, the nature and scope of the license, the licensor’s established policy on licensing, the commercial relationship between the parties, the contribution of the IP to sales, the profitability of the product using the IP, and several others.
An expert who offers a reasonable royalty opinion in a trade-secret case without addressing the Georgia-Pacific factors is offering an opinion disconnected from the analytical framework the court will apply. The royalty number may be reasonable. But if the expert can’t explain how they considered the relevant factors — what comparable licenses exist, what the IP’s contribution to profits is, what the parties would have agreed to in a hypothetical negotiation — the opinion is an assertion rather than an analysis.
For valuation professionals retained in trade-secret or patent damages cases: the Georgia-Pacific factors are not optional. They are the analytical framework the court uses to evaluate reasonable royalty testimony. If you’re unfamiliar with the factors, you need to be before accepting the engagement. And if you’re familiar with the factors but don’t address them in your report, you’re inviting the Daubert challenge that excluded Murray in Wolff. The framework is the methodology. Skip it and the opinion fails.
Gannon’s exclusion for failing to provide testing or data addresses a requirement that applies specifically to technical and engineering experts but has implications for financial experts as well. Under the amended Rule 702, an expert’s opinion must be based on “sufficient facts or data.” For an engineering expert, that means testing, measurement, experimentation, or analysis of physical evidence. An engineering opinion that says “in my experience, this component would fail under these conditions” without testing the component under those conditions is an opinion the court cannot verify.
The parallel for financial experts: a damages calculation that says “in my professional judgment, the royalty rate should be 5%” without citing comparable licenses, analyzing the Georgia-Pacific factors, or grounding the rate in market data is the financial equivalent of an untested engineering opinion. Both rely on the expert’s assertion rather than on verifiable evidence. Both fail under the amended Rule 702 for the same reason: the court has no independent basis to evaluate whether the opinion reflects a reliable application of reliable principles.
The amended Rule 702’s emphasis on sufficiency of data is not a new requirement — it was always in the rule. What the 2023 amendment changed is the procedural posture: the proponent of the expert must demonstrate sufficiency to the court by a preponderance of evidence. The court evaluates sufficiency as an admissibility question, not a weight question. Before the amendment, many courts treated insufficient data as a matter for cross-examination. After the amendment, courts treat it as a matter for the gatekeeping analysis. That shift is what excluded Gannon — and what will exclude the next technical or financial expert whose opinion lacks a sufficient factual foundation.
Wolff brings the expert admissibility cluster to six cases spanning the full range of Rule 702 / Daubert / Frye outcomes:
Total exclusion — wrong credentials: Sullivan v. Loden. Expert lacked domain-specific qualifications.
Total exclusion — unreliable tool: Matter of Weber. AI tool was non-reproducible and unvalidated.
Partial exclusion — mixed components: BBK v. Central Coast Agriculture. Some opinions survived (survey-based apportionment), others didn’t (unsupported assumptions, undisclosed evidence).
Mass exclusion — multiple experts fail: Wolff v. Tomahawk Manufacturing. Three experts excluded for three distinct reasons (unsupported arithmetic, missing framework, no testing data), one for procedural noncompliance, two admitted.
Full admission — record-anchored judgment: Yador v. Mowatt. Expert’s comparable company selection survived because assumptions were tied to record evidence.
Full admission — data-driven simplicity: Kirkbride v. Kroger. Formulaic model using defendant’s own data survived because transparency and evidentiary grounding were unassailable.
Wolff adds the “mass exclusion” position to the spectrum — the case where the amended Rule 702 thins an entire expert roster before trial. The plaintiff walked into the Daubert hearing with six experts and walked out with two. That’s the amended Rule 702 operating at full strength: not just evaluating individual opinions, but evaluating each expert across a multi-expert team and excluding those who don’t independently satisfy the standard.
If you’re assembling an expert team for a trade-secret or IP damages case after Wolff:
Verify that each expert knows the applicable analytical framework. A reasonable royalty expert must be familiar with the Georgia-Pacific factors. A lost-profits expert must understand the Panduit test. A trade-secret valuation expert must understand unjust enrichment and the reasonable royalty alternative under the Defend Trade Secrets Act. If the expert can’t articulate the legal framework their opinion will be evaluated against, the opinion is at risk.
Require data or testing for every technical conclusion. Engineering and technical experts must support their conclusions with verifiable evidence — testing results, measurements, calculations based on known inputs, or analysis of physical evidence. “In my experience” without supporting data is not sufficient under the amended Rule 702.
Distinguish methodology from arithmetic. A damages expert who multiplies a royalty rate by a revenue base is performing arithmetic. The methodology is the process by which the royalty rate was derived and the revenue base was determined. If the methodology can’t be independently evaluated — because the assumptions are unsupported or the analytical framework is missing — the arithmetic is excluded along with the assumptions.
Comply with disclosure deadlines. Dr. Leng’s exclusion in Wolff and the license agreement exclusion in BBK reinforce that procedural compliance is a predicate to admissibility. Expert reports must be timely disclosed, must comply with Rule 26(a)(2)(B)’s requirements, and must be filed in accordance with the court’s scheduling order. No substantive quality saves a report that wasn’t properly disclosed.
Audit the full expert roster, not just the lead expert. Wolff excluded three of six experts. The plaintiff’s litigation strategy presumably depended on all six. Losing half the team before trial restructures the case. Before the Daubert motion is filed, evaluate each expert independently against the amended Rule 702’s requirements. The weakest expert is the one the defendant will target first — and the exclusion of that expert may cascade into the admissibility of the others if their opinions are interdependent.
Wolff v. Tomahawk Manufacturing is the amended Rule 702 at scale: six experts evaluated, three excluded for substantive failures, one excluded for procedural noncompliance, two admitted. Each exclusion was for a different reason — unsupported arithmetic, missing analytical framework, absence of testing data, late disclosure — and each maps to a specific requirement in the amended rule. The two experts who survived did so because their methods were testable, their data was sufficient, and their application of method to facts was transparent and reliable.
For litigation counsel building an expert team: the amended Rule 702 evaluates each expert independently. A strong lead expert doesn’t rehabilitate a weak supporting expert. A credentialed professional doesn’t get in the door just because their CV is impressive. And arithmetic applied to unsupported assumptions is not a methodology, no matter how precise the numbers look. Every expert, every opinion, every assumption must independently satisfy the standard. The court in Wolff evaluated them one by one. Prepare your team the same way.
If you’re preparing a damages analysis in a trade-secret or IP case and need to make sure the reasonable royalty opinion is grounded in the Georgia-Pacific framework, or if you need to evaluate whether your expert team will survive a multi-expert Daubert challenge, happy to discuss the approach. The roster audit before the motion is filed is the most cost-effective expert preparation there is.
Chris Walton, JD, is President & CEO of Eton Venture Services. He can be reached at [email protected].
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