Commercial damages rebuttal expert
Expert class library · Commercial · Defense side
Critiques the opposing damages model by testing its assumptions, inputs, and causal link to the alleged wrong. Often offers an alternative damages figure or explains why none can be reliably measured.
What this expert is retained to answer
- Do the assumptions behind the plaintiff's lost profits projection hold up against the company's actual track record and economic cycles?
- Does the plaintiff's damages model ignore contract terms, historical performance, or market conditions that would reduce the figure?
- Should revenue the plaintiff earned from a replacement transaction be credited against its claimed losses as mitigation?
- Is the plaintiff's yardstick or comparable company a fair analogue for the business that was allegedly harmed?
- Which professional valuation and accounting standards apply to the opposing damages analysis, and were they followed?
Methods
- Assumption sensitivity testing
- Causation and alternative explanation analysis
- Mitigation analysis
- Alternative damages computation
How the testimony is attacked
- No independent damages figure. Plaintiffs argue a rebuttal expert who only criticizes and offers no alternative number has no reliable method. Courts in Washington v. Kellwood and Aviva Sports v. Fingerhut rejected that argument, holding that a defense expert may critique the opposing damages analysis without building a model of his own.
- No recognized method for reviewing another expert. Plaintiffs point to deposition admissions that the rebuttal expert follows no published review methodology. The Kellwood court called that objection tautological, finding the expert's reliance on professional accounting standards was enough.
- Opinions a jury could reach without expertise. Plaintiffs target rebuttal opinions that rest on simple comparisons rather than specialized knowledge. In Insight Health v. Marquis Diagnostic Imaging the court excluded the defense expert's view that the plaintiff could have negotiated a more profitable replacement lease because the jury could draw that inference as easily as he could.
- Misunderstanding of the plaintiff's business. Plaintiffs argue the rebuttal expert misread the data or lacked context about how the business operates. The Insight Health court treated those disputes as matters of weight for cross-examination, not admissibility.
- Critique tied to an abandoned damages calculation. Plaintiffs argue that criticism built on the rebuttal expert's own unreliable or withdrawn calculation must fall with it. The Insight Health court admitted the critique anyway, because a rebuttal expert offering only criticism is not relying on a methodology of his own.
What the public record shows
A deliberately narrow CourtListener search, "lost profits" AND speculative AND "rebuttal expert" AND (Daubert OR "Rule 702"), returned 8 opinions filed since 2015, as of October 2, 2026; broader searches return more. Three that show how courts handle this class of testimony:
| Outcome | Case | Court | Why |
|---|---|---|---|
| Limited | Insight Health Corp. v. Marquis Diagnostic Imaging of N.C., LLC2017 NCBC 14 | N.C. Bus. Ct. 2017 | Applying North Carolina's Daubert-based Rule 702, the court admitted the defendants' rebuttal expert's critique of the plaintiff's profit projections and mitigation but excluded his opinion that more mitigating lease revenue was available, because the jury could draw that conclusion as easily as he could. |
| Admitted | Washington v. Kellwood Co.105 F. Supp. 3d 293 | S.D.N.Y. 2015 | The court refused to exclude the defendant's rebuttal valuation expert, holding that a defense expert may critique the plaintiffs' damages analysis without offering an independent figure and that his reliance on professional accounting standards was a sufficient method. |
| Admitted | Aviva Sports, Inc. v. Fingerhut Direct Marketing, Inc.829 F. Supp. 2d 802 | D. Minn. 2011 | The court denied the plaintiff's Rule 702 motion against the defendant's rebuttal experts, including one who found the plaintiff's lost profits and unjust enrichment opinions speculative, because rebuttal experts may point out flaws in an opposing analysis without offering alternatives. |
Each case links to the free opinion text on CourtListener.
Under amended Rule 702
Since December 1, 2023, Rule 702 says expressly that the party offering an expert must show the court it is more likely than not that the testimony meets each requirement: that it rests on sufficient facts or data, uses reliable methods, and reflects a reliable application of those methods to the case. Questions about the basis of an opinion are no longer automatically matters of weight for the jury. For how the circuits have applied the amendment, see the Rule 702 tracker, which follows each court of appeals; for what that means for preparing or attacking this class of expert, see the guide on amended Rule 702.
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Last reviewed October 2, 2026. How this page is built: rulings are found by searching court opinions on CourtListener, and each one is read in the opinion before it is summarised here; outcomes are labelled by what the court did with the expert's testimony. No individual expert is named. This page summarises public decisions for orientation and is not legal advice; read the opinion before relying on any ruling.