You are technically correct. However, I stipulate that traffic flows more smoothly and more safely and with less delay when both drivers stay to the left edge of the crossover. As soon as a gap appears in opposing traffic, a left-hugging vehicle can immediately proceed with the u-turn or left turn they need to make. Each vehicle at the front of the line has good visibility (the other drivers' line of sight is irrelevant until they are at the front of the line), and each has the opportunity to proceed promptly, and there are no potentials for bumping fenders with opposing vehicles crossing and then turning.
By contrast, staying to the right until past the other vehicle usually creates gridlock (c.f. "human nature") and it requires a rather complicated dance of "who's got right of way." Whenever there are vehicles stacked up in the turn lanes approaching the crossover; there's no clear answer to "who got there first" and neither vehicle is to the right of the other. Thus the normal right-of-way rules are both irrelevant. So there is an increased chance that the vehicles will conflict trying to take the right of way, and even well-meaning, gracious drivers can end up gridlocked. That situation is totally avoided by hugging the left edge.
Note that someone's previous comment about how the left-hugging vehicles cause problems for a vehicle using the crossover to ENTER or CROSS the highway from a side street is (in my opinion) a red herring. In a situation where there are already vehicles stacked up in the crossover turn lane, those waiting vehicles are already in the roadway and thus definitely have the right-of-way. In that case, the side-street vehicles cannot legally enter the same intersection, and thus there is no chance for this situation to cause a conflict.
If the SHA really wanted to make it obvious, then a traffic control device could be implemented - a dashed line indicating correct motion, or a sign indicating what was mandatory. Since they have not chosen to do so, and there is no unambiguous language in the law, I believe it's incorrect to call the left-hugging method "wrong".
