Huh. I think that depends on the laws in Sweden. Nothing in Canada says you need to give up PR statuses from other countries, so if he does lose his PR, it will be because Sweden said so, not Canada.
This is a more question for a forum dealing with immigration to Sweden.
You wouldn't lose Canadian PR automatically if you get one in another country. You'll allowed to be out of Canada for up to 3 years out of every 5 and during that absence, you can pick up as many PR statuses abroad as you want. Not all countries have such a status for people though.