I am not privy to all the details, but if what I remember is that Tesla does specify that you are not to let go of the steering wheel, and that this is what this guys was doing, then I agree with you.
I also think that Tesla by calling it Auto Pilot, which it iclearly is not, made a mistake, giving lunatics ammunition against them.
Actually Elon Musk claimed "The probability of having an accident is 50 per cent lower if you have Autopilot on," said Musk, speaking at an energy conference in Oslo, Norway. "Even with our first version, it's almost twice as good as a person."
Musk set about creating this perception in 2013, when he said that Autopilot would be capable of handling “90 percent of miles driven” by 2016. By mid-2014, Musk was promising investors that the system could handle all freeway driving, “from onramp to exit,” within 12 months of deployment. Tesla still has yet to make good on those bold claims, and competitors argue that Tesla’s relatively simple sensor hardware will never be capable of safely performing at such a high level of autonomy.
Experts have understood Autopilot’s hardware limitations for some time, but Tesla owners and investors clearly believed that Autopilot was either an autonomous drive system, or something very close to it. Brown clearly believed that Autopilot was “autonomous” and described it as such in the description of a video that Musk shared on Twitter.
[NOTE: Musk did NOT correct Brown's beliefs!!! when he shared the video...
] So great was his apparent faith in Autopilot’s autonomous capabilities that he was reportedly watching a DVD at the time of his fatal crash. The extent of Autopilot’s true abilities, which wax and wane with each Over The Air software and firmware update Tesla pushes to the car, is hotly debated on Tesla forums where even Musk’s most devout acolytes waver between extolling its miraculous powers and blaming drivers for their inattentiveness depending on the circumstances.