Can a court set aside a notice of discontinuance filed on behalf of a taxpayer by an agent?

In Baker v. R., [1999] 2 C.T.C. 2388, Bowie J. held that the court had no power to set aside a notice of discontinuance filed on behalf of a taxpayer by an agent. He based his decision upon the implied authority that the agent has to bind his client. He stated that the matter might be different if the agent was simply a friend, professing no particular skill, and assisting the appellant for no consideration. From this I take it that Bowie J. did not consider that there was an insuperable legal bar to the court's power to set aside a withdrawal of an appeal and its consequential deemed dismissal under subsection 16.2(2). Rather it seems clear that he was of the view that the court had the power under some circumstances to do so.