Legal Question in Real Estate Law in California

Re: Landlord loses right after 21 days

It sounds as though you are taking the position that the landlord, having failed to refund any of the deposit within the prescribed three weeks, must now refund the entire deposit. That is not the law.

You are responsible for damage, etc. done to the leased premises whether or not the deposit is returned on time, and not limited to the amount of the deposit. Offsetting this, the landlord is liable to you for your damages resulting from his failure to refund the deposit on time, which will probably only be legal interest on the net amount due you from the due date, PLUS up to $600 as a penalty if the landlord's failure to refund on time was "bad faith," i.e. not just an oversight or caused by legitimate problems in assessing the damage deductions.

Whether the landlord's deductions will stand up in small claims or whether you will win depends upon what the judge believes as to the legitimacy of the deductions. The burden of proof is on the landlord, but that doesn't guarantee your success on each and every item.