What is the burden of proving an affiant's knowledge of falsity?

People v. Cook, supra, makes it clear that once a misstatement has been shown by the defendant, the prosecution has the burden of showing only reasonable grounds to believe the statements were true. The burden is upon the defendant to produce evidence of the affiant's knowledge of falsity. (People v. Cook, supra, at p. 89, 148 Cal.Rptr. 605, 583 P.2d 130.) However the defendant need only prove the affiant's knowledge by a preponderance of the evidence (Id., at p. 89, 148 Cal.Rptr. 605, 583 P.2d 130), and the defendant "will have the benefit of the rule that a sworn misstatement made with conscious indifference to whether it is true or false is deemed the equivalent of an allegation actually known to be untrue." (Id., at p. 90, 148 Cal.Rptr. at p. 618, 583 P.2d at p. 143.)