How do they enforce this? Especially if the card is valid. Does the hospital and doctors office demand to see your passport? How about if someone returned from US? They dont stamp the entry on Canadian passports or what if someone returned to Ontario from manitoba? Or does ohip have an enforcement agency/officers?
In the US , if you apply for Medicaid (state run program), they approve your benefits for one year. And every year you have to come back and re-apply. In the US it is not so much residence that government is concerned about (here you have to kick people out, no one leaves US voluntarily, unlike Canada). But the main concern is the income. If you make more than certain amount per year, then you no longer qualify for free coverage. Now, they don't fly helicopter over your head to see where you work every day, but when you return a year later to re-apply/qualify, they will take a close look at your taxes and other income related documents. I would assume something similar is done in Canada. Your health card may have time limits and expire, like PR card. And eventually, when expired, you will have to qualify and present proof of residence for it. I might be wrong, I just assume that's how it works. But I am sure doctors and hospitals won't ask for a passport or stamp in the passport, that's not how these things work.