As a general proposition, courts are very hesitant to review interlocutory orders of an arbitrator. The Ninth Circuit in Aerojet-General Corporation v. American Arbitration Association, 478 F.2d 248, 251 (9th Cir. 1973) stated that "judicial review prior to the rendition of a final arbitration award should be indulged, if at all, only in the most extreme cases." The court concluded that a more lax rule would frustrate a basic purpose of arbitration of providing for a speedy disposition without the expense and delay of a court proceeding. In Harleyville Mutual Casualty Co. v. Adair, 421 Pa. 141, 145, 218 A.2d 791, 794 (Pa. 1966), the Pennsylvania Supreme Court held that to allow challenges to an arbitrator's interlocutory rulings would be "unthinkable." Massachusetts also rejected the appeal of an interlocutory order in Cavanaugh v. McDonnell & Co., 357 Mass. 452, 457, 258 N.E.2d 561, 564 (Mass. 1970), noting that to allow a court to review an arbitrator's interlocutory order "would tend to render the proceedings neither one thing nor the other, but transform them into a hybrid, part judicial and part arbitrational." Thus Section 18 requires a court to enforce the preaward ruling unless the ruling should be vacated under the standards for confirming, modifying, or vacating awards under Sections 23 and 24.

Courts have considered more closely substantive challenges to preaward rulings of arbitrators on grounds of privilege or confidentiality. In Hull Municipal Lighting Plant v. Massachusetts Municipal Wholesale Electric Co., 414 Mass. 609, 609 N.E.2d 460 (1993), the defendant refused to turn over certain documents to the plaintiff, despite an arbitral subpoena requiring such, because the defendant claimed that portions of the documents contained attorney-client and work- product privileges. After the supervisor of public records had decided issues arising under the public records law, the court concluded that because the matters fell under Massachusetts public records law, the question of privilege was within the discretion of the judge and not the arbitrator. See also World Commerce Corp. v. Minerals & Chem. Philipp Corp., 15 A.D. 432, 224 N.Y.S.2d 763 (1962) (holding that court and not arbitrator decides whether documents of non-party to arbitration are protected as confidential); Civil Serv. Employees Ass'n v. Soper, 105 Misc. 2d 230, 431 N.Y.S.2d 909 (1980) (vacating award of arbitrator who incorrectly determined privilege of patient's confidential records); DiMania v. New York State Dept. of Mental Hygiene, 87 Misc. 2d 736, 386 N.Y.S.2d 590 (1976) (overruling decision of arbitrator regarding client's privilege of confidentiality); compare Great Scott Supermarkets, Inc. v. Teamsters Local 337,