What do we call a situation where two causes result in a loss, with one exclusion and one not?

The situation described, where two causes contribute to a loss—where one cause is excluded from coverage and the other is included—is referred to as concurrent causation. This term is used in insurance contexts to address scenarios in which multiple factors contribute to a loss, highlighting the complex interplay between covered and uncovered risks.

In the case of concurrent causation, the presence of two causes means that even if one cause is excluded from the policy, the other cause's impact may still trigger coverage, depending on the specific wording of the insurance contract. This principle is significant in determining the insurer's obligation to pay for a loss when there are multiple sources of causation.

Other related concepts often confuse learners but are distinct from this scenario. Indirect causation typically involves a chain of events where one event leads to another loss, and supplementary causation does not have a commonly recognized meaning in this context. Primary causation indicates a single, dominant cause of a loss, which differs fundamentally from the concept of concurrent causes influencing the outcome together.