Left Turns Using Multiple Lanes
Not many people adhere to the rule of going into the left lane after a left turn at an intersection - instead they tend to drift across to the curb lane. Should a driver approaching the intersection from the opposite direction and turning right at that place cede right of way to the left-turner? Who would be in the wrong? Common sense suggests that the right-turner give way, even though they could be in the right.
Seems simple, doesn't it? I often wonder why a lot of drivers have so much difficulty turning left correctly as they only have to remember three things; stay to the right of the center line as you enter the intersection, turn left to the left of the center of the intersection and leave the intersection to the right of the centerline, entering the first available lane for the direction of travel.
Of course, we could complicate the issue by adding another step. That would be properly signaling their intention as they approach the intersection.
The right turn driver that you speak of must turn right as closely as practicable to the curb or right hand edge of the roadway. They tend to forget this too and stray over to the left lane. It's a wonder that we don't see more crashes as everyone leaves the intersection.
Who yields to whom is more difficult to answer as it depends how long the left turn vehicle has been present. If the driver has yielded to immediate oncoming traffic and given the proper signal, other oncoming traffic must yield and allow the left turn. This would include our right hand turn driver described in the question.
Finally, if either driver wants to make use of the adjacent lane after finishing the turn properly, they must make a lane change.