What is the burden of proof for a motion where the claim is not proven?

"In determining whether the normal allocation of the burden of proof should be altered, the courts consider a number of factors: the knowledge of the parties concerning the particular fact, the availability of the evidence to the parties, the most desirable result in terms of public policy in the absence of proof of the particular fact, and the probability of the existence or nonexistence of the fact." (Cal. Law Revision Com. com., 29B pt. 2 West's Ann. Evid. Code (1995 ed.) foll. 500, p. 554; see Hellman v. Anderson (1991) 233 Cal.App.3d 840, 853.)