Earlier quoted context omitted.
its not only lines on the road though: Imagine you are following a pickup-truck and out of the back an obviously empty box floats out of the bed and lands directly in front of your car. For a human its trivial to know the box is empty and its ok to hit it....does "AI" know that? Multiply that case x1000 and you have the conditions self-driving cars will need to handle on a daily basis.
If someone drives around with loose crap in the back of their truck that flies out, the truck driver is at fault not the self driving car. This is a danger we already have on the road. Humans make the wrong call on this sort of thing all the time. They also make stupid passes, yield the right of way at the wrong time, drive the wrong way down one way streets, cut each other off, fall asleep at the wheel, drive drunk,…
"It's ok if I get into an accident - it will be the other guy's fault" is only the right reasoning if you're talking on the individual level about about monetary costs of an accident only. If you're talking about injury, or if you're talking about the cost to society as a whole, they are bad consequences regardless of whose fault the accident is.
I think the actual answer is that self-driving cars will end up doing a good enough (i.e. at least human-level but not perfect) job of not wildly swerving or braking to avoid harmless objects like floating plastic bags that this won't be a concern.