Mediation is non-binding. That statement is true, but only up to and until a settlement agreement is reached. In a recent case from the Tennessee Court of Appeals, the Court held that, absent fraud or mistake, once the agreement was reached, the agreement became conclusive. The plaintiff in that case had complained that undue stress and duress had caused him to accept the agreement initially. The Court rejected the claim on certain contract principles.
The lesson simply is this: up and until the basics of the settlement agreement are fixed, mediation is non-binding. At some point in the process, an agreement can be reached on which reliance is based or consideration is given, causing the agreement to become fixed. At that point, unless fraud or mistake is proven (usually by clear and convincing evidence), the agreement will probably be enforced.