In reversing, the Court of Appeal seemingly agreed with the trial court’s premise “that individuals who underwent retesting and retreatment for reasons other than having originally been mistreated would be unable to prove causation” [Slip Opinion, at 11], but disagreed that this issue relegated the causation analysis to a case by case inquiry. Id, at 11-12. As reasoned by the Court, an inference of causation could be premised on class members seeking re-treatment after receiving the March 2004 advisory:
An inference of causation arises when a material event impacts an individual whose subsequent actions constitute a reasonable response. In the class context, where individuals are uniformly subjected to a material stimulus and thereafter uniformly act in a manner consistent with a reasonable response, a classwide inference is raised that the stimulus caused the response.
Here, putative class members all came to the Center seeking treatment for syphilis, a potentially life-threatening disease. They were given the wrong medication. After being informed that the treatment may have been ineffective, they sought retreatment. A reasonable inference as to the entire class is that the initial mistreatment caused members to seek retreatment. Causation can therefore be presumed on common proof.Slip Opinion, at 12-13.
Moreover, while acknowledging that the defendant had a due process right to challenge the presumption individually, the Court concluded that doing so would not entail individualized testimony insofar as such determinations could be made based on treating records in defendant's position:
Though defendant must be given an opportunity to defeat the presumption as to any class member it contends sought retreatment for a reason other than having been initially mistreated, it adduces evidence only as to two such individuals—Aguilar and Rauch. If there are more, it should be a simple matter to ascertain from medical records—most of which defendant already possesses—when most of the class members as to whom causation is disputed received retreatment and whether they indicated they did so for some reason other than the initial mistreatment.Slip Opinion, at 15.
Finally, citing to longstanding precedent, the Court concluded that the individualized nature of damages did not preclude certification. Quoting Sav-On, the Court concluded that the trial court had “‘an obligation to consider the use of … innovative procedural tools proposed by a party to certify a manageable class.’” See id., at 16. As reasoned by the Court, the trial court erred by failing to consider the proposals offered by plaintiffs to streamline adjudication of the damages issue:
Plaintiffs propose a number of ways to streamline the determination of damages, including making exemplar findings to establish a range of recovery, utilizing a proof of claim questionnaire, and establishing a special arbitration forum. Defendant offers no response to the proposals, and the trial court made no comment on them other than to note that they may require defendant to waive its right to a jury trial. Plaintiff's proposals suggest that damages can be determined fairly and expediently. Nothing suggests otherwise. If, after reasonable discovery, it appears that damages in this matter cannot be handled efficiently class wide, the court can divide the class into subclasses or decertify it altogether. (See Vasquez v. Superior Court, supra, 4 Cal.3d at p. 821.)Slip Opinion, at 16.