In Casa Herrera Inc. v. Beydoun (2004) 32 Cal.4th 336, the court held that termination of a civil action based on the parol evidence rule "constitutes a favorable termination for malicious prosecution purposes." (Id. at p. 345.) The court noted that any "concerns over the potential chilling effect of our decision on breach of contract actions due to judicial confusion over the parol evidence rule are readily assuaged by stringent enforcement of the probable cause element of the malicious prosecution tort. By requiring courts 'to make an objective determination of the "reasonableness" of the defendant's conduct' or to determine 'whether any reasonable attorney would have thought the claim tenable' the probable cause requirement adequately protects the breach of contract plaintiff's 'interest "in freedom from unjustifiable and unreasonable litigation." ' " (Id. at p. 348.) "The parol evidence rule is codified in Civil Code section 1625 and Code of Civil Procedure section 1856. It 'generally prohibits the introduction of any extrinsic evidence, whether oral or written, to vary, alter or add to the terms of an integrated written instrument.' The rule does not, however, prohibit the introduction of extrinsic evidence 'to explain the meaning of a written contract . . . if the meaning urged is one to which the written contract terms are reasonably susceptible.' " (Casa Herrera, Inc. v. Beydoun, supra, 32 Cal.4th at p. 343.) The court concluded that a dismissal based on application of the parol evidence rule, a substantive rule of contract law, is a termination on the merits for the purposes of the malicious prosecution rule. (32 Cal.4th at pp. 344-348.) The court distinguished Robbins v. Blecher (1997) 52 Cal.App.4th 886. "In Robbins, the defendants in the malicious prosecution action had filed an alter ego action against the plaintiffs in the malicious prosecution action after obtaining an antitrust judgment against a corporation owned by the plaintiffs." (Casa Herrera, supra, 32 Cal.4th at p. 347.) When the antitrust judgment in Robbins was reversed on appeal, the defendants voluntarily dismissed the alter ego action as moot. In the resulting malicious prosecution action, the plaintiff contended that dismissal of the alter ego action constituted a favorable termination because the defendants could no longer establish a necessary element in light of the antitrust action reversal. (Robbins, supra, 52 Cal.App.4th at p. 894.) The Robbins court held that there was no favorable termination because the dismissal was on technical grounds rather than on the merits. In Casa Herrera, the Supreme Court described the dismissal in Robbins as necessitated by a loss of standing: "The defendants voluntarily dismissed the action because they 'had simply lost standing to pursue' the alter ego action. Thus, in dismissing the action, the defendants had not conceded that the plaintiffs 'had done nothing wrong; they had merely conceded that' they 'were no longer in a position to complain of plaintiffs' wrongdoing.' Unlike the dismissal in Robbins, the Court of Appeal in the underlying action in this case did not rely on a technical or procedural defense like lack of standing. Instead, the court applied a substantive rule of contract law and resolved the action on its merits." (Casa Herrera, supra, 32 Cal.4th at p. 348, second ) In Casa Herrera, Inc. v. Beydoun, the court ruled in favor of the defendant on claims of fraud and breach of contract by applying the parol evidence rule to exclude evidence of prior inconsistent oral promises and by determining that the terms of the written contract mandated dismissal of the claims. The issue on appeal was whether, in doing so, the court in the underlying action had ruled "on the merits." The appellate court found that the prior court's judgment did bear on the merits of the contract and fraud claims: "After defining the terms of the parties' agreement by applying the parol evidence rule, the court then found that appellant did not breach the contract or commit fraud. . . . The court necessarily resolved the underlying action on the merits, and its decision reflects on appellant's innocence of the alleged misconduct. The decision therefore constitutes a favorable termination for malicious prosecution purposes." (Casa Herrera, supra, 32 Cal.4th at pp. 344-345.)