Is a formal judgment document issued by an arbitrator who was mutually appointed binding upon an established Muslim judge?

Primary text

If the arbitrator who was mutually appointed writes down his judgment and sends it to one of the established judges of the Muslims, that judge is obligated to accept it and implement its provisions, because the mutually appointed arbitrator is a judge whose rulings are enforceable, necessitating the acceptance of his writ, similar to the writ of the Imam's official judge.