One inevitable outcome to manufacturing driverless cars is that there will nonetheless be lawsuits if and when those cars get into accidents. And if there's no "driver" to sue, those lawsuits will be undoubtedly be aimed at the manufacturer.
One driverless car manufacturer is trying to avoid liability for several accidents, essentially arguing "to err is human." Tesla says that no manufacturer has been expected to build a perfectly accident-free automobile, especially in the face of human error, nor should it be expected to design a car, even a driverless one, that can overcome those human errors. You can see their full legal filing below: