Having canonical problems like that is a bit of a different thing from whitelists, isn't it?
I have noticed in the past year or so that for many sites, Google seems to "fix" canonical errors on their own back end. This is often the kind of thing that would have tanked a site badly in the past. I'm not sure why they can only do it sometimes and not others - maybe it's related to consistent internal linking.
So I wouldn't consider this to be a kind of whitelist. Canonical URL problems are usually a technical thing, and not really an algorithm factor, per se. Google's has been accommodating more of the common IIS nonsense too. Things like 302 > 200 for not found errors are often not the big issue that they once were.