I think the technical solution has merit. It doesn't need to be voice, presumably you could rig something up on a steering wheel with buttons to press to record

I think the technical solution has merit. It doesn't need to be voice, presumably you could rig something up on a steering wheel with buttons to press to record every time they go past an intersection or something. Something to force them to watch the road and keep their hands in the right area. You're right though, that does dent the image of unattended self-driving but we've already demonstrated that isn't what this was. People are condemning this person for being on their phone (and fair enough), but if I am sitting in a comfortable vehicle with nothing to do / read then I will fall asleep soon enough. I think this is quite common.