Code Civ. Proc., § 2031.300

If a party to whom a demand for inspection, copying, testing, or sampling is directed fails to serve a timely response to it, the following rules shall apply:

(a) The party to whom the demand for inspection, copying, testing, or sampling is directed waives any objection to the demand, including one based on privilege or on the protection for work product under Chapter 4 (commencing with Section 2018.010). The court, on motion, may relieve that party from this waiver on its determination that both of the following conditions are satisfied:

(1) The party has subsequently served a response that is in substantial compliance with Sections 2031.210, 2031.220, 2031.230, 2031.240, and 2031.280.

(2) The party’s failure to serve a timely response was the result of mistake, inadvertence, or excusable neglect.

(b) The party making the demand may move for an order compelling response to the demand.

(c) Except as provided in subdivision (d), the court shall impose a monetary sanction under Chapter 7 (commencing with Section 2023.010) against any party, person, or attorney who unsuccessfully makes or opposes a motion to compel a response to a demand for inspection, copying, testing, or sampling, unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust. If a party then fails to obey the order compelling a response, the court may make those orders that are just, including the imposition of an issue sanction, an evidence sanction, or a terminating sanction under Chapter 7 (commencing with Section 2023.010). In lieu of or in addition to this sanction, the court may impose a monetary sanction under Chapter 7 (commencing with Section 2023.010).

(d) (1) Notwithstanding subdivision (c), absent exceptional circumstances, the court shall not impose sanctions on a party or any attorney of a party for failure to provide electronically stored information that has been lost, damaged, altered, or overwritten as a result of the routine, good faith operation of an electronic information system.

(2) This subdivision shall not be construed to alter any obligation to preserve discoverable information.