From: Rabbi Moshe Sofer
To: Rabbi Moshe Nosson Yosef
When two judges were accepted despite being relatives of the litigants and were selected sequentially (zeh achar zeh), the Chasam Sofer rules that the party in possession (muchzak) may retract his acceptance even after gmar din. Sequential selection creates two separate categories of deficiency (shnei shemos), constituting tartei l'ri'usa in kinship disqualification, which all authorities agree permits retraction. Additionally, the Chasam Sofer rules that communal consent is required for rabbinic appointments, even when a rabbinic position is offered as part of an external arrangement.
Source: Shu"t Chasam Sofer CM §18