What is the standard of review of an order granting a new trial?

We begin with the standard of review. "Upon appellate review of an order granting a new trial, 'all intendments are in favor of the action taken by the lower court [and] the affidavits in behalf of the prevailing party are deemed not only to establish the facts directly stated therein, but all facts reasonably inferred from those stated.' [Citation.]" (Weathers v. Kaiser Foundation Hospitals, supra, 5 Cal.3d 98, 106.) "'When an issue is tried on affidavits... and where there is a substantial conflict in the facts stated, a determination of the controverted facts by the trial court will not be disturbed.' [Citations.]" (Id. at p. 108.)