Score One for the Defense – Court of Appeals Excludes Speculative Expert Testimony because Anything is “Possible”

The Court of Appeals for the Second Appellate District recently affirmed a trial court’s exclusion of expert testimony because the opinion testimony was too speculative to be helpful to a trier of fact.  The decision in Waller v. FCA US LLC, et al. reaffirms the high standards required for admitting expert testimony.


In this case, Lamar Waller purchased a 2013 Dodge Durango manufactured by FCA US LLC (FCA).  Waller sued for breach of express and implied warranties and fraudulent concealment for engine power issues with the vehicle.  Waller’s mechanical expert, Anthony Micale, testified that a faulty fuel pump relay was one of the possible causes of a claimed lack of power in Waller’s car.  Micale also offered additional potential reasons for the power loss, other than the relay.  The trial court ruled that Micale failed to establish the necessary foundation for his expert opinion that the loss of engine power in Waller’s vehicle was related to the fuel pump relay.  The trial court noted that Micale stuck to his “possibility opinion” multiple times, and Micale failed to explain why his opinion showed a probable cause, rather than merely one possible cause.  “Possibilities are irrelevant, because anything is possible,” the court stated.   The trial court excluded Micale’s testimony because it was speculative and failed to aid a jury in understanding the issue and fell short of the standard for expert opinion.


Upholding the trial court’s ruling, the Court of Appeals relied on Sargon Enterprises, Inc. v. University of Southern California  (2012) 55 Cal.4th 747 (Sargon), which provides a detailed explanation of Evidence Code statutes and how they apply in the court’s evaluation of the foundation required to be shown before the court admits expert opinion testimony.  Pursuant Evidence Code Section 801, a trial court must act as a gatekeeper to exclude speculative and/or irrelevant expert opinion, if the type of matter on which the expert relies is unreasonable and if the matter relied upon does not provide a reasonable basis for offering that particular opinion.  Expert opinion cannot be based on speculative or conjectural factors. Further, Evidence Code Section 802 allows a trial court to find that an expert is precluded by law from offering an opinion if there is a significant analytical gap between the data relied upon and the opinion offered based on that data.

The Waller court further applied the analysis from Jones v. Ortho Pharmaceutical Corp.(1985) 163 Cal.App.3d 396, finding that “a possible cause only becomes probable, when, in the absence of other reasonable causal explanation, it becomes more likely than not that the result of this action.”  In Waller, the Court found that there was no expert testimony presented by Micale showing that the fuel pump relay was more likely than not the cause for the engine power issues.  Micale instead testified that it was merely possible, and further testified that there were other potential possibilities.  The Appellate court held that the trial court acted reasonably because Micale’s expert testimony was based on a loose causation analysis, and thus this testimony would not assist a trier of fact.


While Waller is a lemon law case, the court’s analysis regarding exclusion of speculative expert opinion testimony can be applied to all cases, and provides a good  analysis of Evidence Code Sections 801 and 802.  Remember, Anything is Possible, but that Doesn’t make it Probable.  This case will further support our efforts to keep experts from testifying based on speculation as to the cause of alleged complaints, which may translate into more meaningful evaluation of claims, and focus on the actual responsible party, rather than filing claims against every party who could possibly be the cause of plaintiff’s claimed harm.

Submitted by Jennifer Lim