What is the test for establishing probable cause for a plaintiff to bring a malicious prosecution action?

While we reject plaintiff's effort to construe the pleading with undue rigidity, we do not imply that a defendant can avoid liability for malicious prosecution by pointing to some undisclosed and unlitigated, but tenable, claim for relief. (Williams v. Coombs, supra, 179 Cal.App.3d at p. 644, 224 Cal.Rptr. 865.) Probable cause for the initiation of an action depends upon the legal tenability of the action which was actually brought. (Ibid.) We hold only that in assessing the tenability of the action which was brought the complaint must be construed liberally in favor of the pleader rather than restrictively in favor of the malicious prosecution plaintiff.