In Crown Life Insurance Co. v. Casteel, 22 S.W.3d 378, 43 Tex. Sup. Ct. J. 348 (Tex. 2000), the Court ruled that when a single broad-form liability question commingles valid and invalid liability grounds and the appellant's objection is timely and specific, the error is harmful and a new trial is required when the appellate court cannot determine whether the jury based its verdict on an invalid theory. The court of appeals had concluded in the case that the trial court's submission, although error, was harmless because one or more of the valid liability theories were supported by sufficient evidence. Crown Life Ins. Co. v. Casteel, 3 S.W.3d 582, 594-95 (Tex. App.-- Austin 1998), rev'd and remanded, 22 S.W.3d 378, 43 Tex. Sup. Ct. J. 348 (Tex. 2000). The Court disagreed, concluding that the error was harmful because the erroneous submission, over timely objection, affirmatively prevented the appellant from isolating the error and presenting its case on appeal. The Court held that: When a trial court submits a single broad-form liability question incorporating multiple theories of liability, the error is harmful and a new trial is required when the appellate court cannot determine whether the jury based its verdict on an improperly submitted invalid theory. See TEX. R. APP. P. 61.1 ("No judgment may be reversed on appeal ... unless the Supreme Court concludes that the error complained of ... probably prevented the petitioner from properly presenting the case to the appellate courts."); see also TEX. R. APP. P. 44.1(a). Casteel, 22 S.W.3d at 388. The broad-form jury question commingled fourteen liability theories, four of which could not provide a basis for recovery because the plaintiff was not a consumer under the DTPA. 22 S.W.3d at 386-387. The Court noted that the jury "was given no indication that Casteel was required to be a consumer to succeed under any of the liability theories," and held that a single broad-form liability question that erroneously commingles valid and invalid liability theories is harmful "when it cannot be determined whether the improperly submitted theories formed the sole basis for the jury's finding." Id. at 389. The decision was based on the notion that "it is fundamental to our system of justice that parties have the right to be judged by a jury properly instructed in the law." Id. at 388. Thus, the Court determined it "essential that the theories submitted be authorized and supported by the law governing the case." Id. at 389. The Court held that "when a single broad-form liability question erroneously commingles valid and invalid liability theories and the appellant's objection is timely and specific, the error is harmful when it cannot be determined whether the improperly submitted theories formed the sole basis for the jury's finding. " Id. at 389.