I've been driving in Canada (Ontario) for years, but have never quite understood one thing.

Here's a scenario I see on a regular basis:

Car A and Car B are both turning into the same street, from opposite directions.

The street they're turning onto has two lanes.

The rule of the road as I learned them says you turn into the lane nearest you, then move over once it's safe to do so.

(image: http://i.imgur.com/ARLDsJy.png)

So, Car A will turn into the lane it's nearest, then when it's safe will move over.

Car B will turn into the lane it's nearest, then if required to turn left/overtake will move out when it's safe to do so.

My question is: If one of the driver turns into the wrong lane (pretty common), and there's an accident, who is at fault?

It seems pretty clear that Car B doesn't have to yield to Car A here (there's not yield lane for him to turn right). If Car A turns at the same time and turned directly into the slow lane (image: http://i.imgur.com/nFEcvdB.png), it would seem pretty clear Car A was at fault.

However I'm a little fuzzier on what happens in the other situation. Car B turns right, but turns into the fast lane (either because he needs to turn left quickly, or to overtake), and hits Car A (image: http://i.imgur.com/qG4CiWy.png)

In that case, who would be found to be at fault? Car B turned into the wrong lane, but should Car A have waited till the junction was completely clear? Like, not just the lane closest to him?

If I'm Car A in the second situation, I'll normally try err on the side of 'the other guy's probably an idiot', but at the same time you can't impede traffic behind you.

Do you go, and assume the other guy will pick the correct lane? If he doesn't, will he (generally at least) be found at fault?

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#EDIT:

There are 2 comments that give completely opposite answers. It appears the one that's being upvoted is not correct. (Not a reflection on u/modest_rodent, I've asked many people IRL as well, and got differing answers) u/dittomuch gave an authoritative source

http://www.mto.gov.on.ca/english/dandv/driver/handbook/section2.4.3.shtml

If you are turning left, you must wait for approaching traffic to pass or turn and for pedestrians in or approaching your path to cross.