Seems to me that there's a robustness issue with the system.
It seems REALLY obvious to me that a natural and high possibility in this mode is for a tired driver to fall asleep.
Which means they need a better way of dealing with it. And if the car had lane control and brake control (which I would presume it does, given what it can do)- it should be capable of making it hard for a driver to go from basically asleep to making sudden inputs.
Not to say that it's not driver's fault, and that he fell asleep. But that Tesla does need to figure out a better way of dealing with it. It's going to happen again- 100% of that.