I agree with the Ninth Circuit that it makes sense to certify this question to the Nevada Supreme Court. But were I on the latter, I also am confident which way I'd answer the question.
Four people who are staying at the Casino West Motel die of carbon monoxide poisoning when fumes from the motel's pool heater room seep into their individual rooms. Casino West has an insurance policy, but the insurance company denies coverage. It does so based on two exclusions in the policy. One of these is a mold exclusion. The other excludes coverage for pollution, though not pollution from equipment used to heat the building or from a fire.
The literal terms of either exception might well apply. That's because, as with every insurance policy, the actual words that are used have a virtually limitless extension. I nonetheless think that a reasonable insured would expect coverage for carbon monoxide poisoning notwithstanding the presence of exclusions that are clearly designed to bar claims for mold, asbestos and the like. This may be one of those particular perils that you don't actually think much about when you sign the policy, just because it's relatively rare. But if you did think about it, you'd definitely think you're covered, because stuff like that is precisely why you get insurance.
We'll see if the Nevada Supreme Court agrees.