This is probably true.  Most Canadians who are well informed about the case know that there is far more to it that the ones who jump aboard the comments pages to type "murderer, terrorist, treason!" repeatedly.  They know the Gitmo confession is questionable, that he was 15 and himself badly wounded in combat (in which people were trying to kill him as well) and that three Canadian governments failed to do their job.  The more one reads and hears about the Khadr saga, the less easy it is to sympathize with the so-called 'conservative' position about the case.
At the close of WW2, the Nazis, in desperation, recruited boys as young as Khadr to fight. While the issue of their citizenship obviously doesn't come into play, it's quite possible they too killed or wounded some Allied soldiers, and there is no hesitation in regarding them as 'child soldiers.'
I think Ibbitson is wrong, and that very few votes will be swayed by this decision.