27.—(1) The arbitrator must, in awarding costs, take into consideration —
(a)the reasonableness or unreasonableness of the claim of any party, whether in respect of the amount or otherwise;
(b)any unreasonable demand for particulars or refusal to provide particulars; and
(c)generally all the circumstances of the case.
(2) The arbitrator may disallow any costs which he or she considers to have been unnecessarily incurred, including the costs of any witness whom he or she considers to have been called unnecessarily.