4. Sections 12(c), (d), and (e) seek to accommodate the tensions between concepts of partiality and the need for experienced decision makers, as well as the policy of relative finality in arbitral awards. Therefore, in Section 12(e) a neutral arbitrator's failure to disclose "a known, direct, and material interest in the outcome or a known, existing, and substantial relationship with a party," gives rise to a presumption of "evident partiality" under Section 23(a)(2). Cf. Minn. Stat. Ann. § 572.10(2) (1998) (failure to disclose conflict of interest or material relationship is grounds for vacatur of award). A person who has this type of interest or relationship, in the absence of agreement by the parties, is not to serve as a neutral arbitrator under Section 11(b). Failure to disclose that type of interest or relationship creates the presumption of vacatur in Section 23(a)(2). In such cases, it is then the burden of the party defending the award to rebut the presumption by showing that the award was not tainted by the non-disclosure or there in fact was no prejudice. See, e.g., Drinane v. State Farm Mut. Auto Ins. Co., 153 Ill. 2d 207, 214-16, 606 N.E.2d 1181, 1184-85, 180 Ill. Dec. 104, 107-08 (1992). A party-appointed, non-neutral arbitrator's failure to disclose would be covered under the corruption and misconduct provisions of Section 23(a)(2) because in most cases it is presumed that a party arbitrator is intended to be partial to the side which appointed that person.

Section 12(d) involves instances other than "a known, direct, and material interest in the outcome of the arbitration proceeding or a known, existing, and substantial relationship with a party" of an arbitrator's failure to disclose that do not create a rebuttable presumption of evident partiality by a neutral arbitrator but nevertheless may be a ground for vacatur under Section 23(a)(2).

Section 12(c) covers instances where the arbitrator makes a required disclosure, a party objects to that arbitrator's service, but the arbitrator overrules the objection and continues to serve. In the situation of a disclosed interest or relationship, the presumption of evident partiality in Section 12(d) does not apply even if the disclosure involved "a known, direct, and material interest in the outcome of the arbitration proceeding or a known, existing, and substantial relationship with a party."