I have a lot of experience jumpseating out of Toronto. Usually the agents don't really know how to tax you properly. I don't know what airline you work for but if its any airline other than NW they probably taxed you using the OAL rate which is 32 and change. If you work for NW or one of the operating regionals you should have been put at a different rate. Usually its just as easy to non-rev out of Toronto unless you JS on AC or Jazz who don't charge the departure tax.