If the presiding officer or other agency official responsible for the original proceeding would not have authority over the new proceeding to which it is to be converted, the agency head shall appoint a successor to preside over or be responsible for the new proceeding.
Source:
Section 11470.20, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=GOV§ionNum=11470.20.
.