Legal Question in Criminal Law in California

Huh? Once an attorney becomes a judge, that person cannot practice law unless they retire from the bench. An attorney who is inactive is also not allowed to practice law.

An Appellate Court "Justice" may act as a mediator. I seriously doubt that they are practicing law.

Judges are not members of the State Bar and as such are not entitled to practice law. A judge who leaves the bench and wishes to practice law must apply for readmission to the State Bar. Retired judges are sometimes assigned to hear cases, and sometimes they hire themselves out as referees or mediators.