California Code, Probate Code - PROB § 2103

(a) When a judgment or order made pursuant to this division becomes final, it releases the guardian or conservator and the sureties from all claims of the ward or conservatee and of any persons affected thereby based upon any act or omission directly authorized, approved, or confirmed in the judgment or order. For the purposes of this section, “order” includes an order settling an account of the guardian or conservator, whether an intermediate or final account.

(b) This section does not apply where the judgment or order is obtained by fraud or conspiracy or by misrepresentation contained in the petition or account or in the judgment or order as to any material fact. For the purposes of this subdivision, misrepresentation includes, but is not limited to, the omission of a material fact.