Oh yes, there are very significant differences between the Arar and Khadr cases. Chief among them, Maher Arar endured 'just' a year of abuse in a foreign prison. Omar Khadr spent almost 10 years in a foreign prison, during which time the Canadian government participated in his abuse and prolonged his incarceration.

The misinformation on Mr. Arar that the Canadian government passed to the Americans was in error, but it was an honest one. No malice was intended. Surely we can agree that the government didn't expect him to be tortured in a Syrian prison over it. However in the Khadr case, agents of the Canadian government actively violated his rights, and knowingly benefited from the abuses he suffered.

If you believe that the Charter should apply equally to all citizens, no matter how distasteful the circumstances, then Khadr's alleged crimes are of no relevance. Yet the transgressions of the Canadian government in the Khadr case are far worse.