So the Federal Court has ruled that prisoners taken by Canadian troops in Afghanistan are not due the rights of the Canadian Charter, but are due the rights of international humanitarian law.
That would seem to be pretty clear cut, even after a cursory reading of the Third Geneva Convention, that Canadian transfers of prisoners to the Islamic Republic of Afghanistan, which has not signed any of the Geneva conventions, are illegal.
I've asked the question directly of the International Committee of the Red Cross, and await their response with interest.