He has to take both sides, like every court which takes the defendants arguments into consideration, even when he's not there. This is not our point. Arbitration should be voluntary from the beginning and explicitly agreed upon by both sides of the deal. Not unleashed upon someone from atop, even with the best (stated above) practices. They maybe typical of all arbitrations, but these points are not the only ones typical. We argue that unilateral nature of the filed claim is in fact not arbitration but external ruling, resembling a court without executive power (since the arbitrator is not a BP, so no execution can take place).