What the doctrine means
When a loss results from a sequence of events, efficient proximate cause asks which peril was the dominant, moving force that started the chain. If that predominant cause is a covered peril, the loss is treated as covered even if a later link in the chain is excluded, and the reverse is also true. The doctrine is a way to assign one controlling cause to a loss that had several contributing events.
How Florida treats combined causes
Florida is notable for generally applying the concurrent cause doctrine rather than a strict efficient proximate cause rule when two or more independent perils combine to produce a single loss. Under the concurrent cause doctrine, coverage can exist if a covered peril was one of the contributing causes, even when it was not the predominant one, which tends to favor policyholders. An anti-concurrent-causation clause in the policy can change this result by contract, so the specific policy language controls.
Why it matters for your claim
Carriers often frame a mixed loss around an excluded cause to justify a denial. Understanding which causation framework applies, and what the policy actually says, can turn a denial into a partial or full recovery. The key move is proving the covered peril's role in the loss with dated photos, weather data, and independent inspection.