Tell him this is the advice you are relying on. If he want something different, ask him to provide a third party reference to say whatever he asked for was legal and reasonable.
https://www.latimes.com/archives/la-xpm-2000-oct-01-re-29583-story.html
"Current law states that you have 21 days from the husband’s departure to return the deposit. When returning the deposit in this case, the check should be made payable to both husband and wife, making the usual deductions for damages and cleaning."