Another USA/quebec tax question

Hi, I'm new to the boards, and I've read some discussions here about US/Canada tax issues, but didn't find any on this exact problem.

I'm a US Citizen married to a Canadian citizen from Quebec. We met and married in the US almost 3 years ago and he's now a permanent resident. I have never lived in Canada.

We filed taxes jointly in the US, as we have since we got married, and we sent copies of our tax forms and information on his income to his accountant in Quebec. We heard back from that accountant, with completed provincial tax forms, and it seems my spouse owes quite a bit of taxes there, despite having only US-source income. He does still have some bank accounts and investments in Canada, so I don't think he qualifies as having "severed all ties." It also looks, from the amount of income reported, like the Quebec government might be taxing him on BOTH our incomes. That doesn't make sense to me. How can my income as a US citizen be subject to provincial taxes in a country where I've never been a resident? Is this legal?

You need to explain to RQ that he is non-resident. What ties he has in Québec are irrelevant, he's married to a US citizen and resides in the US, that is a very strong residential tie. However if the bank is still spitting out T5s and sending them to the CRA, they may still think he is resident. On his last T1 he should have noted on page 1 that he had left the country. Obviously they're not psychic and they don't know he's non-resident until he tells them.

Also he should probably have filed dual-status in the US when he initially moved there, as explained in IRS publication 519.