There is no grey area when it comes to the settlement. It has nothing to do with what did or didn't happen in that compound in Afghanistan. The settlement is strictly regarding the actions and non-actions of the Canadian government when Khadr was held at Guantanamo Bay.
The Harper government went to court to have Khadr's sentence declared an adult sentence. The Supreme Court of Canada ruled against them.
https://www.theglobeandmail.com/news/national/omar-khadr-youth-or-adult-question-decided-by-top-court/article24421830/
It amazes me that people rely on anything that came out of Guantanamo Bay as being the truth. It opened in 2002 and still has detainees there as of January, 2017. Of the 775 people who were detained there, there were a grand total of 8 convictions and 4 of those have already been overturned on appeal. The American government ignored international law - holding people for years without charges and no access to counsel, torturing/killing detainees and the list goes on. The only kangaroo court in this case is the US military commission.