What happens if an arbitrator makes a mistake in a conclusion of law?
The decision rendered by a private arbitrator is "99.9 %" binding and neither party can appeal the result. Even "an error of law apparent on the face of the [decision] that causes substantial injustice does not provide grounds for [an appeal]." California Supreme Court in the Moncharsh decision (1992). In other words, if the arbitrator adds 2 + 2 and says that totals 5, too bad, his or her decision cannot be appealed to the courts to correct the error. Added: The above answer may be true and applicable in California, but it is not the prevailing rule in all states. Judgements made by lesser judicial officers, arbitrators, magistrates, justices of the peace, etc, are subject to the review and over-rule by a judge of the appropriate court. If the arbitrator (et al) makes an error that is not caught by the judge, the aribitrator's ruling may be appealed and possibly overturned by higher judicial authority.