Sheldon Appel Co. v. Albert & Oliker (1989)
527.6 is not basis for a claim of malicious prosecution.

According to published case Siam v. Kizilbash

"We conclude that pursuant to the policy enunciated in Sheldon Appel Co. v. Albert *372 & Oliker (1989) 47 Cal.3d 863, 254 Cal.Rptr. 336, 765 P.2d 498 (Sheldon Appel), a cause of action for malicious prosecution may not be based upon an unsuccessful civil harassment petition. (§ 527.6.) " (Siam v. Kizilbash, 31 Cal. Rptr. 3d 368)

However, we have yet to find to what in Sheldon Siam found to support its ruling that malicious prosecution is not available.  But Siam's reason seems to be yet another judicial cop-out.

From Siam,

"Yet, as in family law disputes, the background of bitterness would make it difficult to distinguish between a malicious petition and one that is not malicious. Further, just as in family law matters, section 527.6 provides for attorney fees as sanctions for a frivolous petition. "

So, shall we also bar a defamation action in the background of a "bitter" divorce?

Nothing contained herein is tendered as nor should it be considered as legal advice.  What is legal is not necessarily justice.  Almost all of reality is non-"published", ergo, what is legally affirmed is always a retarded misrepresentation of reality.   Use at your own risk!