Exactly. It's not so much a legal thing (note the use of "rules" vs "laws" in my earlier comment) as much as it is a practical thing. If you're a Tesla owner, it's not going to be a good experience if using Smart Summon results in your car getting stuck in a one-way lane. If you're the driver of a car that ends up face-to-face with a driverless Tesla that is going the wrong way, it's also going to be a bad experience. And if the Tesla does somehow get in a collision, I think you would have a hard time coming up with an excuse to your insurance company as to why your car was going against established traffic flow.

It probably gets legal when a collision happens.

Also, when one gets a person who drives the wrong way, maybe one has a good chance to make them reverse. Good luck with a car without a driver.