You may want to consider taking him to small claims. You may also want to consider getting an attorney involved to see if he/she can settle this matter without having to go to court given this is your landlord. In either case, it would be unlawful for your landlord to retaliate against you if you decided to exercise your right to seek the money he owes you.
By posting on this site or answering/responding to questions does not create an attorney-client relationship and is intended to be an opinion only. My opinion is not intended to be a guarantee or promise of any outcome or result in your matter.
There is a theoretical and a practical answer to this question, and they are different.
THEORETICALLY, it is illegal for your landlord to 'retaliate' against you for pursuing your legal rights to collect a debt he owes you.
PRACTICALLY, your landlord has already proven to be a jerk and a scammer, so it would be highly likely that he will retaliate in some way - legal or not!
If he will not pay voluntarily, it will probably cost close to (or more) than $600 to get an attorney involved. So, your real alternatives are to convince him to pay and/or file a small claims action.
By the way, you should be VERY careful about "handyman" work if you are not a licensed contractor! California law forbids lawsuits by unlicensed persons to collect on work which would require a contractor's license if the amount is over $xxx (I think the number is 600, but I am not sure).
If you need further clarity, please email me at MICHAEL@MIRELAND.US Answers to questions are for general information purposes only and do not establish an attorney-client relationship. This is not legal advice, simply information. You SHOULD NOT act on this information without consulting a competent bankruptcy attorney in your area and providing ALL relevant information.