That is exactly the sort of situation self-driving cars are expected to be perfect, or at least superior, to humans at handling. If they're no better than a human driver or even a bit worse when edge-cases occur than what's the point?
[0]: http://www.mercurynews.com/2015/01/23/chp-tackles-surge-in-s...
That said, I think GP will be proven right in time. Risk compensation[0] is a well-documented phenomenon and this seems highly likely to trigger that sort of behaviour.
One of the biggest mistakes you can make is to believe that the news is an accurate reflection of reality. The opposite is actually true, in the sense that what makes it to be high profile news is something unusual and surprising.
They might get political pressure to consider high attention events instead of the statistics, but they are partly in the business of pushing back against that kind of pressure.
Make the autopilot ring alarm when uncertainty reaches some point and that's it. Tesla already can do it, but doesn't do it for some reason.
It's going to get to a point where they say it's all or nothing, we can't rely on people to stay attentive when the car is doing 90% of the driving.