What is the standard of review for a motion to set aside the 2004 Notice of discontinuance?

The parties agreed that the 2004 decision was a nullity because of the lack of a properly constituted quorum. They agreed to a rehearing. The terms of that rehearing are in dispute but that will be discussed later. As stated in Chandler v. Alberta Association of Architects, 1989 CanLII 41 (SCC), [1989] 2 S.C.R. 848, a tribunal may always rehear a matter anew if its original decision was vitiated by an error rendering it a nullity. It does not have to wait for a court order to do so. That is what happened here. So, even if there were grounds to set aside the notice of discontinuance, there is nothing to judicially review with respect to the 2004 decision since it was a nullity. Standard of Review: