first, this is a landlord forum,....so you're sort of asking the quire how they sound. that being said, $400. doesn't go very far these days, especially in CA.. You can fight it in small claims court and the judge will probably split the difference at best (for you) as you acknowledge there was some damage. then there's your aggrevation factor. Perhaps you just want to consider it retroactive additional rent and get on with better things.