California Code, Code of Civil Procedure - CCP § 634

Whena statement of decision does not resolve a controverted issue, or if the statement is ambiguous and the record shows thatthe omissionor ambiguity was brought to the attention of the trial court either prior to entry of judgment or in conjunction with a motion under Section 657 or 663, it shall not be inferred on appeal or upon a motion under Section 657 or 663 that the trial courtdecided in favor of the prevailing party as tothose facts or onthat issue.