You're putting a lot of weight on the distinction between drowsy and sleep deprived in a casual comment at the end. How many people really know the distinction

You're putting a lot of weight on the distinction between drowsy and sleep deprived in a casual comment at the end. How many people really know the distinction and use the correct word in the correct situation? He's clearly looking at it from a UI design perspective and other issues like you mentioned aren't the point of the article. Accidents have multiple causes. Somebody else might blame sleep deprivation and stimulants then a smart-ass would complain that they just waved away "confusing controls" without understanding how they worked.