What is the test for deliberate secrecy in the adjudication process?

At the core of the principle is protection of the substance of the matters decided and the decision-maker’s thinking with respect to such matters: Tremblay v. Quebec (Commission des affaires sociales),1992 CanLII 1135 (SCC), [1992] 1 S.C.R. 952 at 964-65. Deliberative secrecy also extends to the administrative aspects of the decision-making process - at least those matters which directly affect adjudication – such as the assignment of adjudicators to particular cases: MacKeigan v. Hickman, 1989 CanLII 39 (SCC), [1989] 2 S.C.R. 788 per McLachlin J (as she then was) at 831-33.