“As a result of a series of interrelated Civil Code provisions, a plaintiff who has prevented the defendant’s performance under their contract or has induced the defendant’s nonperformance is barred from suing for breach and is instead liable for breach. Moreover, if the defendant’s lack of performance was caused by operation of law, the defendant may again rely on prevention of performance as a defense. A defendant whose performance is prevented by operation of law is not liable for breach of the contract. A defendant who has been sued for breach of contract should review the events leading to the alleged breach to determine if the plaintiff’s conduct or the operation of law was a causal factor in the prevention of the defendant’s performance.”
[California Affirmative Defenses [certain citations omitted]]
