As someone who actually used to live in a foreign country, I'm not sure you can determine that easily. I was a resident of Australia for certain purposes and I was a resident of Canada for other purposes. For income tax purposes, I did my taxes here as opposed to there, but I was working there. Actually, I was a permanent resident of Australia.
What I'm getting at is that I think Mr. Simard has a good point. It's basically impossible to determine in the absence of a declaration, unless somebody has gone out and actually done something like rejecting their Canadian citizenship in order to become a citizen of another country, which some countries require.