FewMiles,
Although those may have been and continue to be the rules they were certainly not enforced this last year or so when it was possible to purchase a RTW ex Canada at Canada rate from U.S. In interpreting the rules the key question is where does trip begin. If one travel once or several times a month it is hard to say where exactly your trip begins. If the rule were keyed to domicile or residence that might be another issue.
At any rate, does anyone know a good Canadian travel agent?