BHG, the driver wasn't "driving", so, naturally, will lose interest. If you are a passenger with someone else driving, do you honestly pay full attention throughout the whole journey, and never drift off into your own thoughts, because you aren't actually doing anything?
However optimistic it is, I just can't see how this combination will ever be safer.
And these people know they are testing! This is the most careful that "drivers" will be. Imagine when we are all used to it and getting blase about it.