Can Previous Boss/landlord Sue Me For Restitution On A Closed Case?

It’s a long story that I won’t get into unless you need the backstory of course but essentially I was charged with using my boss’ cc (>$50) and was sentenced to a 3rd degree misdemeanor. Received a 6mo probation with no restitution. (He made it clear that he had been reimbursed by the bank and didn’t want to double dip) Originally he was trying to have me charged with over $4k of charges on his card however he/his lawyers were unable to prove anything. Prior to this I had filed charges against my boss both with the police and with HUD bc yes, he was my landlord as well. I am now at a conciliation point with HUD between myself and my previous boss/landlord who is stating that if I move forward with my claim they will sue me for the restitution that they previously wanted but did not receive. Can they do that? Even though this case has already been settled and is closed?