In an insured's diversity contribution action against its excess insurance carrier, the district court's judgment in favor of the insured, award of attorney fees and denial of defendant's motion for certification of an issue to the California Supreme Court are affirmed where: 1) concerning plaintiff's breach of contract claim, the district court correctly followed the Diamond Heights Homeowners Ass'n v. Nat'l Am. Ins. Co., 227 Cal. App. 3d 563 (1991) rule in this diversity action governed by California law because the case had not been overruled and was not distinguishable; and 2) concerning the bad faith claim, the district court correctly concluded that the genuine dispute doctrine was subsumed within the standard Judicial Council of California Civil Jury Instructions for breach of good faith and fair dealing, which the district court gave to the jury.