That seems crazy, and with the statute you have years to do this?  I would think it has to be a steep uphill battle when only one party, after a year or two someone is bound to be better of with a rescission.  I would think you need overwhelming evidence here or this would be abused regularly..??? IMO

"Mutual Consent Of The Parties: A contract may always be rescinded upon the mutual consent of the parties thereto. But rescission at only one party's behest requires proper notice on statutory grounds and, if necessary to adjust the equities, a court action to enforce the rescission. [Ca Civil §§ 1689, 1691, 1692] "