What is the burden of proof for a plaintiff in a motor vehicle accident insurance claim?

recent case upon which Washington relies, Vardanyan v. AMCO Ins. Co. (2015) 243 Cal.App.4th 779: "'When an issue of coverage exists, the burden is on the insured to prove facts establishing that the claimed loss falls within the coverage provided by the policy's insuring clause.'" Neither case states this burden is "light," and Washington offers nothing to demonstrate the proper burden is not the normal civil burden of proof, a preponderance of the evidence.

Indeed, one case the trial court relied upon summarizes the relevant issues: "An insurance policy is written in two parts: the insuring agreement defines the type of risks which are covered, while the exclusions remove coverage for certain risks which are initially within the insuring clause. [Citation.] Therefore, '. . . before even considering exclusions, a court must examine the coverage provisions to determine whether a claim falls within the potential ambit of the insurance.' [Citation.] This is significant for two reasons. First, '. . . when an occurrence is clearly not included within the coverage afforded by the insuring clause, it need not also be specifically excluded.' [Citation.] [] Second, although exclusions are construed narrowly and must be proven by the insurer, the burden is on the insured to bring the claim within the basic scope of coverage, and (unlike exclusions) courts will not indulge in a forced construction of the policy's insuring clause to bring a claim within the policy's coverage. [Citations.] Thus, the plaintiff has the burden of establishing that there has been an 'accident' or 'occurrence.'" (Collin v. American Empire Ins. Co. (1994) 21 Cal.App.4th 787, 802-803, italics added.)