Two insurance companies both covered the same construction company. When a lawsuit arose, Fireman's Fund paid for the defense and settlement costs. Fireman's Fund then sued Maryland Casualty to recover its share of those costs. Maryland argued it didn't have to pay because the insured had already settled with them. The California court ruled that one insurer can demand payment from coinsurers for defense costs without needing the insured to have a valid claim against the other insurer. This matters to subcontractors because it clarifies how insurance companies split costs when multiple policies cover the same project.
If you're covered by multiple insurance policies, each insurer can be forced to pay its fair share of defense costs even if the insured has already settled with another insurer
Equitable contribution between insurers is separate from subrogation—one insurer doesn't need the insured's permission or remaining claims to recover from coinsurers