That's only partially true - the original Charter violations were committed by CSIS and DFAIT officials under Chretien and Martin's watches.  However, Harper not only took 6 years to get Khadr out of Guantanamo  - after every other western country had gotten their citizens out - but he spent millions fighting it at every step.  

Had Harper done that early on, there's little doubt he could have settled all of Khadr's claims for pennies on the dollar at the same time.