In what circumstances will a former judge and his or her new law firm be disqualified from acting as a mediator?

[39 Cal.App.4th 125] We agree with the analysis in Poly Software that disqualification of both the individual attorney and his or her firm is required where the attorney has been privy to confidences of a litigant while acting as a neutral mediator. We also agree with the distinction drawn between adjudicators and mediators, so long as the adjudicator does not become a mediator and, in doing so, receive confidences from the parties going to the essential merits of the dispute. Where a judicial officer has presided over settlement conferences which included ex parte communication, we presume the revelation of confidences relating to the merits of a litigant's case. The same principles discussed in Poly Software demand disqualification of both the former judge and his or her new firm in such circumstances. The case for disqualification of the judge is even more compelling than the case of the mediator, who has a far more limited role in a matter than a judge. In California, "[t]he usual role for a settlement judge is mediation, i.e., 'intermediating between two contending parties with a view to persuading them to adjust or settle their dispute.' [Citation.]" (Mohn v. Kohlruss (1987) 196 Cal.App.3d 595, 598, 242 Cal.Rptr. 110.)