In a motion for summary adjudication on a motion to exclude evidence as to drainage, does plaintiff need to explain to the arbitrator why it was necessary to exclude the evidence?

In addition, plaintiff did not explain the basis for the arbitrator's rulings on the evidentiary issues. In excluding the evidence as to drainage he issued a well-reasoned and complete nine-page order. In that order, among other things he discussed plaintiff's argument that a prior denial of a motion for summary adjudication regarding Settlement No. 1 had been denied. The arbitrator relied on case law that denial of summary adjudication did not preclude him from ruling on the motion to exclude evidence. (Salehi v. Surfside III Condominium Owners' Assn. (2011) 200 Cal.App.4th 1146, 1158.) Plaintiff has not cited law to the contrary.