The idea that the driver didn't know he was supposed to have his hands on the wheel while using autopilot seems ridiculous. Anyone who has used autopilot knows

The idea that the driver didn't know he was supposed to have his hands on the wheel while using autopilot seems ridiculous. Anyone who has used autopilot knows that failure to keep the hands on the wheel results in a warning. We do know he received warnings. And we can strongly infer that he knew how to actively avoid receiving warnings. Therefore I can't possibly fathom how Tesla could be responsible for a "failure to warn".