Problem is was it malfunction ? Driver is always required to pay full attention and it is just a driver assist.
Clearly, by your definition Autopilot cannot malfunction ever. Then why go on raising the point that Autopilot didn't malfunction, when you think it will always be a perfect system, even if it decided to mow down pedestrians
Are you serious? The car decided to turn and hit a divider at 60mph without ever attempting to brake.
The reason the driver is required to pay full attention is because the software malfunctions in some cases.
If the car drove itself into a barrier without a malfunction, it's a design defect.
If the car didn't drive itself into a barrier, well, that's a different story.