I don't think that is a contradiction. It means that there are some situations (probably traffic jams) where the car can fully drive itself, instead of merely assisting you as you drive the car.

If there's a need for a human to take over (e.g. traffic jam dispersed and the car can no longer drive autonomously), that's not full autonomy (Level 5), that's weasel-autonomy (or, more charitably, Level 4): "autonomous, autonomous, auton-gotcha, not autonomous, that block straight ahead is your problem now." That does sound familiar, doesn't it.