Arbitration is an extension of the principles of contract - that free parties are entitled to make agreements between themselves. In this case they agree that any disputes are resolved via an arbitor. There are some legal restraints but the choice of arbitor and the way he deals with the case is largely unrestricted. This is for good reason - the circumstances of the dispute can vary hugely as can the particular areas of expertise that would make an arbitor a good choice to resolve it.

The decision is generally binding but it must be a fair decision - and failure to do that is typically the only ground for appeal. Appeal is to the civil court system and fairness is decided in accordance with established secular legal values - not those of dark age religious teachings.

It should be great, but it is obviously open to a party to make a less than well informed decision as to who they want as arbitor. And ignorance of the limits of the system could mean that unfairness isn't challenged.