Civ. Code, § 2960

If information disclosed in accordance with this article is subsequently rendered inaccurate as a result of any act, occurrence, or agreement between the parties to the transaction subsequent to the delivery of the required disclosures, the inaccuracy resulting therefrom shall not constitute a violation of this article. If, at the time disclosure is to be made, an item of information required to be disclosed is unknown or not available to the vendor, purchaser, or arranger of credit, and the arranger of credit has made a reasonable effort to ascertain it, the disclosure may employ an approximation of the information, provided the approximation is clearly identified as such, is reasonable, is based on the best information available to the arranger, and is not used for the purpose of circumventing or evading the provisions of this article.