Omar Khadr has been tortured and abused by an ally, the government of the United States of America. Therefore, though there is some press coverage, the government will do nothing about it. The government will say that Khadr was in league with terrorists and that American justice must be allowed to run its course - even if the U.S. Supreme Court has ruled Guantanamo bay to be illegal.
Huseyin Celil, however, is a worthy victim. He's accused of terrorism in China. China is an human-rights abusing enemy and must be confronted. Consequently:
The Conservative government initially took a firm stance on Mr. Celil's case – senior government officials said they saw no evidence that Mr. Celil was involved in terrorism, and the Canadian's case was championed at the highest levels of government in Ottawa.
You can see how this works. Human rights abusing enemies must be confronted while human rights abusing allies must not.
You can see the similarity. Both are accused of terrorism. In both cases there is no evidence (Even if Khadr threw a grenade, it wouldn't be "terrorism"). In both cases they are Canadians. In both cases they are incarcerated in violation of international agreements.
But the Canadian government ignores Khadr as much as possible, pretending American justice will serve Canadian interests while even the U.S. Supreme Court is doubtful. And Celil? The government works to get him in the news, even when we're just talking about benefits for his wife.