Here's the background to this case: Omar Ahmed Khadr (September 19, 1986 - ) is the 4th child in the Canadian Khadr family. He has been imprisoned in the Guantanamo Bay detention camps since he was captured at the age of 15 following a firefight between American troops and Afghan irregulars. He is accused of throwing a grenade that killed a US soldier, leading to charges of war crimes and providing support to terrorism. Born in Toronto, his case has drawn considerable attention as a child soldier who is the youngest prisoner held in extrajudicial detention by the United States to face charges in the War on Terror. The only Western citizen remaining in Guantanamo, Khadr is unique in that Canada has refused to seek extradition or repatriation.Wikipedia
It's very difficult to have sympathy for Khadr, when one looks at the history of his family's links to terrorism. This CBC report is from 2006, and gives a profile of each member of the Khadr family: CBC. However, that said, nobody should have to wait 6 years for a trial, and endure the conditions that Khadr has in Guantanamo Bay.
And, as your first link said, in the last few days, new information has come to light that suggests that Omar Khadr may not have been the person that threw the grenade that killed an American soldier in the first place. The Globe and Mail: Doubt cast on allegations against Omar Khadr
The Khadr case is a difficult one. Here is somebody whose family has known links to terrorism, but at the same time has not had access to basic human rights. He was 15 when he was sent to Guantanamo. He is 21 now and still awaits trial. Now there are doubts about whether he threw the grenade that killed the US soldier. Why isn't Canada trying harder to get him out of American custody? I think its a combination of support for the US, and a perhaps our government's (and the public's) unsympathetic feelings for him and his family here. Regardless of his background, I think we need to be seen to do the right thing, I'm sure the Canadian government will be facing a huge lawsuit at the end of all this, brought by the Khadr family. More on the case here: Khadr's lawyers claim Canada, U.S. violated rights of terror suspect