In Department of Fish and Game v. Superior Court (Adams), ___ Cal.App.4th ___ (Aug. 2, 2011), the Court of Appeal (Third Appellate District) reversed an order granting class certification of causes of action for public nuisance, negligence, and inverse condemnation. The action arose out of the Department of Fish and Game's decision to attempt to eradicate the northern pike, an invasive species of fish, from Lake Davis in Plumas County by poisoning the lake. Slip op. at 2-3.
The Court of Appeal held that the trial court "applied an erroneous procedure in assessing the evidence":
The trial court described its task in analyzing the evidence on the question of whether common issues predominate as follows: “The proper legal criteria is whether the declarations presented by Plaintiffs constitute substantial evidence that predominant factual and legal issues make the case more amenable to class treatment. When looking at Defendants’ declarations, the relevant inquiry is whether they rebut Plaintiffs’ substantial evidence.” This description suggests the court first examines the proponent’s evidence in isolation to determine if it satisfies the proponent’s burden of showing that common issues predominate and then looks at the opponent’s evidence to see if it rebuts that showing. In light of the trial court’s description of the expert evidence, as described above, it appears that is in fact what the court did. However, that is not the proper procedure.
... [When ruling on class certification,] the court does not look at the parties' evidence under a shifting burden of proof. The burden remains with the proponent of class certification to show common issues predominate. However, when assessing whether the plaintiff has satisfied that burden, the evidence must be evaluated under the prism of the plaintiff’s theory of recovery. What that means in the present matter is that the evidence must be examined in light of plaintiffs’ theory that the 2007 poisoning caused an overall decline in property values and economic activity, regardless of whether some members of the class may not have been harmed thereby.
Slip op. at 35-36, 38 (citing Jaimez v. DAIOHS USA, Inc., 181 Cal.App.4th 1286 (2010)).
The 65-page opinion discusses a variety of other issues.