Final answer:
The rule that applies when a loss is caused by both an insured peril and an uninsured peril, with coverage deemed to apply, is known as concurrent causation.
Step-by-step explanation:
The legal rule you are referring to is known as concurrent causation. This is applicable when a loss is the result of both an insured peril and an uninsured peril. Under the rule of concurrent causation, if a covered risk and an uncovered risk both contribute to a loss, the insured is still able to get coverage for the loss.
Insurance policies often detail how they deal with losses caused by multiple factors, which might affect the application of the concurrent causation doctrine. This concept is particularly important in understanding the intricacies of insurance contracts and how insurance companies assess claims when multiple causal elements are involved.