This is my concern. CRA always has the ability to review a tax situation for a number of years (7?). If an assessment error was made, there could be a significant tax liability, especially if CRA were not provided with accurate information.CRA customer service is often wrong unfortunately. It seems highly likely that he has been a tax resident since moving abroad and leaving his family in Canada. If your family is in Canada benefitting from things like education and healthcare parents are expected to contribute into the tax base if they are PRs or citizens. Seems logical. I would call CRA a couple of times to see if you Geta consistent answer or just ask an accountant,