Does a denial of a right to a fair hearing always render a decision invalid?

This follows the decision in Cardinal v. Kent Institution, 1985 CanLII 23 (SCC), [1985] 2 S.C.R. 643, where Le Dain J. stated at para. 23: … I find it necessary to affirm that the denial of a right to a fair hearing must always render a decision invalid, whether or not it may appear to a reviewing court that the hearing would likely have resulted in a different decision. The right to a fair hearing must be regarded as an independent, unqualified right which finds its essential justification in the sense of procedural justice which any person affected by an administrative decision is entitled to have. It is not for a court to deny that right and sense of justice on the basis of speculation as to what the result might have been had there been a hearing.