As we have discussed in our Causation summary, where multiple distinct, separate causes of a loss are involved, some of which are covered and some of which are excluded, most courts will make a coverage determination based on either a “concurrent causation” analysis, or the “efficient proximate cause” rule, in the absence of specific policy language governing causation.

However, some property policies provide explicit language that certain excluded losses are excluded regardless of whether another covered cause of loss is at issue. Typical anti-concurrent causation language provides that the loss will be excluded “whether or not any other cause or event contributes concurrently or in any sequence to the loss.” This anti-concurrent causation clause is typically included as part of only a small number of exclusions, including water damage, earth movement, nuclear hazard, etc.

While the vast majority of jurisdictions enforce anti-concurrent causation language in property policies under the basic principle of freedom of contract, a minority of jurisdictions have determined that insurers cannot contract around the jurisdiction’s public policy interest in enforcing the efficient proximate cause rule. There are four jurisdictions that do not enforce anti-concurrent causation clauses: California and North Dakota have statutes that courts have held to preclude enforcement of these clauses. Washington State courts have followed the California authority. The West Virginia Supreme Court has refused to enforce anti-concurrent causation clauses as a matter of judicially-adopted “public policy.” See Murray v. State Farm Fire & Cas. Co., 203 W. Va. 477 (W. Va. 1998).