Is a discretionary order of a prothonotary valid on appeal?

In Canada v. Aqua-Gem Investments Ltd.[1], Mr. Justice MacGuigan, for the majority, wrote at page 463: ... discretionary orders of prothonotaries ought not to be disturbed on appeal to a judge unless: (a) they are clearly wrong, in the sense that the exercise of discretion by the prothonotary was based upon a wrong principle or upon a misapprehension of the facts, or (b) they raise questions vital to the final issue of the case. Where such discretionary orders are clearly wrong in that the prothonotary has fallen into error of law (a concept in which I include a discretion based upon a wrong principle or upon a misapprehension of the facts), or where they raise questions vital to the final issue of the case, a judge ought to exercise his own discretion de novo.