Cal. Lab. Code § 3727.1

The director may withdraw a stop order or a penalty assessment order where investigation reveals the employer had secured the payment of compensation as required by Section 3700 on the date and at the time of service of such order. The director also may withdraw a penalty assessment order where investigation discloses that the employer was insured on the date and at the time of an injury or claimed injury, or where an insured employer responded in writing to a request to furnish the status of his workers’ compensation coverage within the time prescribed.