Just Cause Eviction but did not state reason in notice

[Siobhan Loftus]

I am a landlord in California. I recently had a new tenant that stated that a person was going to stay with them for a couple of weeks to help them move in.  However when that time past, and I asked when the guest was leaving, the tenant said that the guest was going to stay a couple of months. I told the tenant that I did not agree to making the guest an additional tenant.  In response the tenant said that she was going to vacate by the end of the month but then stated she was not giving legal notice to end the tenancy. I told her that she needed to give legal notice in writing which she refused to do so I gave her 30 day notice to make intentions clear for all concerned.  She still moved out by by month end but prior to the expiration of the 30 day notice. I returned her security deposit minus the rent for the remainder of the 30 day term. 

This was in April 2021 so it was during the current eviction moratorium.  I thought I was in the right to give a 30 day notice at that time (because it was prior to one year of tenancy) but apparently that legislation changed. Apparently a landlord cannot give a "No Cause" notice even before 1 year now. So she has now sent me a demand letter for $3000.00 for alleged violation of the Eviction moratorium and numerous other codes.  After some research I now realize that I did not state a "Just Cause" reason in the 30 day notice and I should have given the 3day notice to cure, etcetera instead. 

If we end up in court will the judge see that this is in fact a "Just Cause" eviction based upon our correspondence and evidence and that I simply made a procedural error in not submitting the proper notice? Or am guilty or liable simply based on the fact that I did not use the proper notice during the eviction moratorium?  If I am "guilty/liable" is there penalties for this or is the notice simply considered defective? 

Any input would be appreciated. Thanks.