What is the test for but for and what is the effect of the but for test?

To be clear, while the language of “but for” and “causation” originally emerged from the law of negligence, these concepts have since developed separately in the context of interpreting insurance coverage. In the field of negligence, the “but for” test of causation is used to determine whether the loss suffered occurred as a result of the wrongdoing of the defendant: Clements v. Clements, 2012 SCC 32, [2012] 2 S.C.R. 181. But in the insurance interpretation context, fault is not required for coverage to be engaged, unless specified in the policy. In fact, many insurance policies provide coverage for losses even when no party is identified as being at fault, as is the case here.