Legal Question in Mediation in California

Re: what can be done about a non-neutral mediator

Sadly, the law has a long way to go in spelling out the ethical/legal duties of a "neutral" mediator. Whether the mediator was an attorney also affects what his/her ehtical obligations are. Oftentimes a mediator will "beat up on" one side of the case if that party is being completely unreasonable. Many people choose mediation for just that purpose - to give one of the party's a "reality check" from an impartial observer. I assume you were not represented by counsel at the mediation.

Short answer, no, the facts you describe do not rise to the level of duress. Was there a written agreement or memorandum of understanding signed by you and the other party? As to the other question, you have no recourse if you voluntarily entered into the agreement, absent any showing of collusion or bribery of the mediator.