I don't believe it is, actually. If the cigarette is stamped, this offence would not apply. If the cigarette is stamped it means that the federal excise tax has been paid, but there are provincial taxes that have to apply as well.
Theoretically, it would be possible for an officer or an employee of a cigarette company to sell stamped cigarettes, but in a manner as to avoid provincial sales tax, and so be able to sell cigarettes that are less than the going price. He would be caught by provincial revenue statutes then. But I don't think he would get caught by this—