California Code, Probate Code - PROB § 406

(a) The authority of a person to act as a probate referee ceases immediately upon expiration of the person's term of office, revocation of the person's appointment, or other termination pursuant to law.

(b) Upon cessation of authority of a person to act as a probate referee, the Controller shall notify the superior court of the county for which the probate referee was appointed. Upon receipt of notice, or if it otherwise comes to the attention of the court that the authority of a person to act as a probate referee has ceased, the court shall reassign any estate for which the person had been designated as probate referee to another probate referee.