Opinion ID: 2831421
Heading Depth: 3
Heading Rank: 2

Heading: McKinney’s Assumptions

Text: Courts must “rigorously examine the validity of the facts and assumptions on which [expert] testimony is based[.]”Camacho, 298 S.W.3d at 637. If an expert’s opinion is unreliable because it is “based on assumed facts that vary from the actual facts,” the opinion “is not probative evidence.” Id.; see also Burroughs Wellcome Co. v. Crye, 907 S.W.2d 497, 499–500 (Tex. 1995) (“When an expert’s opinion is based on assumed facts that vary materially from the actual, undisputed facts, the opinion is without probative value and cannot support a verdict or judgment.”). This does not mean that an expert’s factual assumptions11 must be uncontested or established as a matter of law. If the evidence conflicts, it is the province of the jury to determine which evidence to credit. See Cooper Tire & Rubber Co. v. Mendez, 204 S.W.3d 797, 804 (Tex. 2006). Nor does it mean that parties must prove up every inconsequential assumption on which their expert relies. But if the record contains no evidence supporting an expert’s material factual assumptions, or if such assumptions are contrary to conclusively proven facts, opinion testimony founded on those assumptions is not competent evidence. See TXI Transp. Co. v. Hughes, 306 S.W.3d 230, 237–40 (Tex. 2010) (distinguishing expert testimony in case from unsupported assumptions relied 11 We reference here “factual assumptions,” meaning assumptions about the facts of the case or the specific data on which the expert relies to reach an opinion in the case. We do not reference the kinds of scientific, mathematical, or other technical assumptions or presumptions that may be regularly and reliably employed in an expert’s area of expertise. 19 on by expert in Volkswagen, 159 S.W.3d at 904–06); Cooper Tire & Rubber, 204 S.W.3d at 804 (“[I]f an expert’s opinion is based on certain assumptions about the facts, we cannot disregard evidence showing those assumptions were unfounded.”) (quoting City of Keller v. Wilson, 168 S.W.3d 802, 813 (Tex. 2005)); see also Williams v. Ill., 132 S. Ct. 2221, 2241 (2012) (“[I]f the prosecution cannot muster any independent admissible evidence to prove the foundational facts that are essential to the relevance of the expert’s testimony, then the expert’s testimony cannot be given any weight by the trier of fact.”). A contrary approach would allow parties with the burden of proof on a particular fact (such as causation) to avoid the obligation to put forth evidence by simply instructing their expert to assume the fact in forming their opinions. McKinney’s damages opinion rests on several assumptions and leaps of logic. First, she assumes that the diminutions she found for the Sebastian and Sheridan sites were both 100% attributable to contamination that occurred and had been remediated on nearby land. She then reasons that because those two sites suffered diminutions as a result of remediated contamination, the ranch also suffered a diminution as a result of its remediated contamination and the proportionate amount of that diminution will be more than that suffered by the Sheridan site and less than that suffered by the Sebastian site. Even if we accept that the Sebastian and Sheridan sites suffered diminutions in their market value, those diminutions are relevant here only if they were attributable to the remediated contamination. But McKinney did not attempt to establish that the remediated contamination near the Sebastian and Sheridan sites caused some or all of the diminution in market value she found, nor did she attempt to rule out other plausible causes. Cf. Wal-Mart Stores, Inc. v. Merrell, 313 S.W.3d 837, 840 (Tex. 2010) (“An expert’s failure to explain or adequately disprove alternative theories of causation makes his or her own theory speculative and conclusory.”); General Motors 20 Corp. v. Iracheta, 161 S.W.3d 462, 470 (Tex. 2005) (“[The expert] eliminated the obvious possibility that fuel or vapors from the tank filler neck ignited only by saying so, offering no other basis for his opinion. Such a bare opinion was not enough.”). Instead, McKinney simply assumed that 100% of the asserted diminution in value in both sites was attributable to the remediated contamination. This kind of material assumption, entirely lacking evidentiary support, renders expert opinion testimony unreliable and incompetent to support a judgment. See TXI Transp., 306 S.W.3d at 239–40 (discussing the Volkswagen expert’s “assumption that the detached wheel remained pocketed in the wheel well throughout a turbulent and high-speed accident sequence,” which he failed to “connect his theory to any physical evidence in the case or to any tests or calculations prepared to substantiate his theory”); see also Sage Street Assocs. v. Northdale Constr. Co., 863 S.W.2d 438, 449 (Tex. 1993) (observing that an expert’s assumptions do not constitute evidence). McKinney seems to have operated under the assumption that all remediated property will suffer market stigma. While the parties agreed that environmental contamination can result in a diminution in property value that remains even after the contamination is remediated, the parties did not agree, and there was no evidence indicating, that this is always the case. Absent such evidence, we cannot assume, without evidence, that any (much less all) of the diminution McKinney found for the Sebastian and Sheridan sites was attributable to market stigma. And even if there were such evidence or evidence that contaminated properties always retain some diminution in market value even after remediation, Mel Acres offered no evidence tending to show that all of the Sebastian and Sheridan sites’ alleged diminutions in value were attributable to stigma or to apportion such diminution among stigma and other possible causes. 21 The evidence here, in fact, indicates other potential causes of the “diminution” McKinney found. With respect to the Sheridan site, the difference between the original list price and the verbal offer price may reflect the difference between what the seller hoped to get and what a buyer hoped to pay rather than any actual change in the property’s market value. And if there was a change in the property’s market value, because both the original listing (the “unimpaired” market value) and the verbal offer (the “impaired” market value”) occurred after the contamination and its remediation, the impairment of the property’s market value cannot, without more, be attributed to the contamination. With respect to the Sebastian site, the only evidence indicates that the difference between its sale price and two other comparable sales prices simply reflected the “sweetheart” nature of the deal. The record does not conclusively establish any of these alternative plausible causes as the actual cause. But Mel Acres offered no evidence tending to establish that the asserted diminutions were attributable, in whole or in part, to the contamination near the Sheridan and Sebastian properties. Absent any evidentiary basis, McKinney’s material assumptions that the diminutions she found were caused by contamination-related stigma that remained after remediation of the property are unsupported and render her opinion incompetent and no evidence. Cf. Wal-Mart Stores, 313 S.W.3d at 839–40 (holding that expert’s causation opinion lacked evidentiary value when factual basis for opinion was equally consistent with alternative cause); Volkswagen of Am., Inc. v. Ramirez, 159 S.W.3d 897, 911 (Tex. 2004) (noting that expert’s causation opinion was based on facts that were “just as consistent with” the expert’s opinion of what happened as they were with an alternative course of events). 22