I wonder about this too. If you are new to CA, at first it seems crazy how aggressive people are about splitting the right hand lane to turn right... who would have the right of way if the bus was already stopped at a light, but the AV split the lane to turn right and passed the stopped bus? I like the idea of splitting the right lane to make right turns, but IMO, if you've done so, you no longer have the right of way for traffic in that lane.