Radford v. Shehorn, said that such testimony would only be allowed if the parties agreed to it, meaning that it is hard to think of a situation where testimony by the mediator would ever be permissible or useful. (But see this post by Vickie Pynchon on another (unpublished) case where the mediator was permitted to testify that a written agreement the insurance company was seeking to enforce conformed to what the parties agreed during the mediation.)
In the Radford case, there was a dispute between two sisters about whether the parties entered into a binding agreement at the mediation. The disgruntled sister claimed she had only consented to the second handwritten page of a document prepared during the mediation, which was titled "settlement agreement," but which she contended was not intended to be binding unless and until a more formal agreement was prepared. She denied that the first page of the document, which contained statutory language making the agreement enforceable, was part of the agreement that she signed. Her sister introduced a declaration by the mediator stating that both pages of the document were distributed to the parties, therefore implying that their signatures on the second page applied to both pages.
The Court of Appeal held that the first page did contain the necessary language that waived confidentiality, and thus would permit the mediator to testify. Nevertheless, the Court held that the mediator was still barred from testifying about whether that page was included in the agreement the parties signed. That would breach California's strict statute making the mediator incompetent to testify as to what occurred at the mediation. In other words, if there was a valid agreement waiving confidentiality, the mediator could have testified. But the mediator could not help prove whether there was in fact a valid agreement waiving confidentiality. All was not lost for the sister who supporting enforceability of the agreement, however, because the Court of Appeal was able to construe the remaining admissible declarations, including the declaration by the objecting sister, in such a way as to affirm the result below.
The lesson is that the parties may rely on the mediator to help them arrive at an agreement, but cannot count on the mediator's help to prove that an agreement was in fact entered into. If the parties want the agreement to be enforceable, they should take adequate precautions to make sure it stands on its own.
(photo from aBitofAll)