A model where a driver is assumed to disengage attention, etc but then be expected to rengage in a fraction of a second to respond to an anomalous event is fundamentally at its core flawed I think. It's like asking a human to drive and not drive at the same time. Most driving laws assume a driver should be alert and at the wheel; this is what...? Assuming you're not alert and at the wheel?
As you're pointing out, this leads to a convenient out legally for the manufacturer, who can just say "you weren't using it correctly."
I fail to see the point of autopilot at all if you're supposed to be able to correct it at any instant in real-world driving conditions.
-The cynic in me suggests we need autopilot as a testbed on the way to the holy grail of Level 5 autonomous vehicles.
The engineer in me fears that problem may be a tad too difficult to solve given existing infrastructure - that is, we'd probably need to retrofit all sorts of sensors and beacons and whatnot to roads in order to help the vehicles travelling on it.
Also, highway lane splits are very dangerous in general. It's a concrete spear with 70mph cars whizzing right towards it. Around here, they just use barrels of material, sand I believe. Somebody crashes into one, they clean the wreck, and lug out some more sand barrels. Easy and quick.
For the foreseeable future, there's simply too many variables outside autopilot manufacturers' control; I cannot see how car-borne sensors alone will be able to provide the level of confidence needed to do L5 safely.
Oh, and a mix of self-driving and bipedal, carbon-based-driven ones on the roads does not do anything to make it simpler, as those bipedal, carbon-based drivers tend to do unpredictable things every now and then. It'll probably be easier when (if) all cars are L5.
So - humans need to adapt to new behaviour from other vehicles on the road.
When ALL vehicles are L5, though, they (hopefully) will all obey the same rules and be able to communicate intent and negotiate who goes where when /prior/ to occupying the same space at the same time...
And, of course, they should all obey the same rules (well, traffic regulations being one, but also how they handle the unexpected - it would be a tough sell for a manufacturer who rather damaged the vehicle than other objects in the vicinity in the event of pending collision if other manufacturers didn't follow suit...
Autonomous Mad Max-style vehicles probably isn't a good thing. :/
-This is the scariest bit, IMHO. Basically, autopilot is well enough developed to mostly work under normal conditions; humans aren't very good at staying alert for extended periods of time just monitoring something which mostly minds its own business.
Result being that the 'assist' runs the show until it suddenly veers off the road or into a concrete barrier, bicyclist, whatever. 'Driver' then blames autopilot; autopilot supplier blames driver, stating autopilot is just an aid, not a proper autopilot.
This is the worst of both worlds. Driver aids should either be just that - aids, in that they ease the cognitive burden, but still require you to pay attention and intervene at all times - or you shouldn't be a driver anymore, but a passenger. Today's 'It mostly works, except occasionally when it doesn't' is terrifying.