It's an unpublished decision and not certified for publication.  Nevertheless, the analysis of the interplay between the anti-concurrent causation clause and the efficient proximate cause doctrine described in Rouland v. Pacific Specialty Ins. Co., G040299, 2009 Cal. App. Unpub. LEXIS 2589 (Cal. Ct. App. March 30, 2009) warrants attention. 

    The insured's home suffered damage following a landslide, which occurred in part due to water leaking from a broken sewer pipe.  Pacific denied coverage because: (1) loss due to leakage from a plumbing system that occurred over a period of time was excluded; (2) the loss did not fall within the policy's coverage for collapse due to "hidden decay" because no part of the house collapsed and there was no decay to any part of the home; and (3) the policy excluded coverage for harm due to earth movement and water damage.  The trial court granted summary judgment to Pacific.

    On appeal, the court first determined that the home had "collapsed" within the meaning of the policy.  The policy covered "collapse" if caused by "hidden decay."  Pacific argued the water leak was the cause of the damage, not "hidden decay."  However, the insured's expert had determined underground corrosion caused the sewer pipe to leak. The corrosion and decay of the pipe led to the loss of the structural integrity to the pipe and the pipe's ultimate failure. Coverage was therefore triggered because the structure had collapsed due to ""hidden decay" of the pipe.  Although Pacific argued the hidden decay had to be located in the structure itself, the policy simply read, "hidden decay." 

    Preceding the exclusions for earth movement and water damage was an anti-concurrent causation clause:

    We do not insure for loss caused directly or indirectly by any of the following.  Such loss is excluded regardless of any other cause or event contributing concurrently or in any sequence to the loss.

    Given the broad reach of this clause, the specific exclusions for earth movement and water damage would require denial of the claims because it was undisputed that the landslide and water damage contributed to the loss.  But in California, Insurance Code section 530 incorporated the efficient proximate cause doctrine into all policies in determining whether a loss falls within an exclusion.  The court explained that under this doctrine, when a loss is caused by a combination of a covered and specifically excluded risk, the loss is covered if the covered risk was the efficient proximate cause of the loss, meaning the "predominant" or primary cause of the loss.

    Therefore, a triable issue of fact existed based on the insured's expert's determination that underground corrosion caused the sewer pipe to leak.  Accordingly, the fact that earth movement and water damage occurred in the chain of causation did not mean the loss was excluded under the policy.

    It is unlikely Hawai`i courts would reach a similar result because there is no equivalent of Insurance Code section 530 under Hawai`i law.  Therefore, the anti-concurrent causation clause would bar coverage.