The biggest reason for the difference between Autonomous vehicles and peanut butter is that with autonomous vehicles, we already have a compliance system in place....cops. It's not designed for autonomous vehicles, and you are correct that it's not the way you would design it for the ground up for autonomous vehicles, but it's far better to accept the imperfections than to build some new, separate compliance and monitoring system on top of the existing one. The benefits aren't large enough to justify it.
In the far future when the vast majority of vehicles are autonomous? Sure, probably worth scrapping to a new system (by then, my guess is that issues are rare enough to just not have a system at all and just use the legal system in the rare cases of large issues).
Until then, ticketing in the case of traffic violations seems fine and good enough to me.