In Aydin Corp. v. First State Ins. Co. (1998) 18 Cal.4th 1183, the court held that the insured seeking indemnity had to prove that the claim came within the "'sudden and accidental'" exception to the general pollution exclusion. (Aydin, supra, 18 Cal.4th at pp. 1185-1186, 1194.) This conclusion makes sense in the context of the duty to indemnify, which requires proof of actual coverage as opposed to a mere potential for coverage. As the party advocating for actual coverage, the insured should have to prove actual coverage under the exception. But in the duty to defend context, the rule requires only potential coverage, and the insured must show only a potential for coverage. The Aydin court recognized that its holding was limited to the duty to indemnify context, and the duty to defend was not at issue in the case. (Id. at p. 1194, fn. 6.)