Legal Question in Employment Law in California

You will be liable for the overpayment. Do not know the statute of limitations on the claim in California. But even if they could not sue you, your reputation would be shot if and when the loss is discovered. So, to avoid civil suit, and a bad reference forever, if not worse, I would self report and arrange a payment plan. "Self reporters" usually do not get "the book thrown at them." Otherwise, you probably will.