But giving the money back now would bankrupt the company, which no government would do. And since the people involved are powerful donors, no politician will even mention holding the people responsible.
Air Canada/France/whatever is not just a company. It's an important aspect of globalisation and the country whose flag it carries treats it as such. Transformation into a formal corporation is usually a ploy to make it cost effective. And, in many countries, is only partial, often resulting in the worst of both worlds.