In Roberts v. Sentry Life Insurance (1999) 76 Cal. App. 4th 375, a trial court's denial of summary judgment compelled the conclusion there was probable cause, because the denial implied the judge found at least some merit in the claim, and probable cause was lacking only in the total absence of merit. Roberts found that denial of summary judgment is a reliable indicator of probable cause, principally because the judge denying summary judgment is impartial, and her denial accurately predicts that reasonable lawyers would find a case arguably meritorious. (Ibid.) In Roberts v. Sentry Life Insurance, the court stated and applied a well-established principle sometimes referred to as the "interim adverse judgment" rule. The rule is that "an interim adverse judgment on the merits, even though subsequently set aside on motion or on appeal, conclusively establishes probable cause for the prior action." ( Crowley v. Katleman, supra, 8 Cal. 4th at p. 692, fn. 15.) The rationale for the rule is that "approval by the trier of fact, after a full adversary hearing, sufficiently demonstrates that an action was legally tenable." ( Roberts v. Sentry Life Insurance, supra, 76 Cal. App. 4th at p. 383.) For example, a victory at trial, though reversed on appeal, conclusively establishes probable cause to bring the action. ( Cowles v. Carter (1981) 115 Cal. App. 3d 350, 355, 358, 171 Cal. Rptr. 269 "the true basis for the rule . . . may be articulated in the following question: Did a trier of fact after a fair adversary hearing reach a determination on the merits against the defendant in the prior proceeding?".) Roberts extended the interim adverse judgment rule to include an interim adverse ruling denying summary judgment. The court reasoned that denial of a defendant's summary judgment motion "provides similarly persuasive evidence that a suit does not totally lack merit." ( Roberts v. Sentry Life Insurance, supra, 76 Cal. App. 4th at p. 383.) Roberts observed the trial court must find there is a triable issue of material fact and the defendant is not entitled to judgment as a matter of law. These conclusions, Roberts states, "necessarily imply that the judge finds at least some merit in the claim." (Ibid.) The court cited two considerations showing that denial of summary judgment is a "reliable indicator" of probable cause. First, summary judgment rulings "usually are grounded in a dependable evaluation of the facts," because motions are heard only after full discovery develops the evidence relevant to the claim. (Ibid.) Second, the judge denying summary judgment is impartial, and the judge's assessment "likely will agree with some hypothetical 'reasonable lawyers,'" and so "accurately predicts that reasonable lawyers would find a case arguably meritorious." ( Id. at pp. 383-384.)