Daubert and unreliable assumptions

In Jacked Up LLC v. Sara Lee Corp., the plaintiff’s expert “seems to have assumed
that the projections in the Sara Lee Pro Forma were correct and then extrapolated lost-profits figures.” But the record also contained a detailed explanation by the defendant’s marketing director about why “the assumptions in the pro formas are merely
elaborate guesswork by the business and sales teams” until there are actual product sales. Accordingly, the Fifth Circuit affirmed the exclusion of the expert under a basic Daubert principle: “Expert evidence that is not ‘reliable at each and every step’ is not admissible.” No. 19-10391 (April 3, 2020) (unpublished). (citation omitted). (LPHS represented the successful appellee in this case.)