It's true and a major factor that Alfie highballed the Sens as his intention was to explore the Canadian tax system. It is not a loophole, it is clearly stated. Something to the tune of 17 million or so (although I can't remember the actual figure)will come his way in two years time. The taxes he paid over the years will be returned. Shawn Simpson has alluded to this a few times that the tax implication for Alfie to leave are too big to ignore. As was Sundin's decision to go back to Europe, and other players who then return.
I don't believe there is any retroactive benefit.
It has to do with what the CRA calls significant residential ties to Canada which include:
•a home in Canada;
•a spouse or common-law partner in Canada; and
•dependants in Canada;
Secondary residential ties that may be relevant include:
•personal property in Canada, such as a car or furniture;
•social ties in Canada, such as memberships in Canadian recreational or religious organizations;
•economic ties in Canada, such as Canadian bank accounts or credit cards;
•a Canadian driver's licence;
•a Canadian passport; and
•health insurance with a Canadian province or territory.
By selling the house Alfie will file in the US and save considerable tax dollars because the US Federal tax rate is lower for high income earners and the Michigan state tax is almost non-existent compared to Ontario.
As far as players jumping back to Sweden to save tax, find that hard to believe when Sweden's tax rate is higher than Canada.
Individuals pay both national income tax and municipal income tax. In 2010, individual income tax rates in Sweden change between 54% and 61%, 57.77% being the average tax rate.
While the average tax rate for a Swedish player residing in Ontario would be 46.03% in 2014.
In the case of Alfredsson living in Michigan, his average tax rate is ~40%.