I think this is the thing that makes the most sense. But if I were to bend over backwards giving the benefit of the doubt - is it possible the driver feared resuming the previous speed because they were worried the car saw an obstacle that they couldn't?
Like the article suggests - if you're not fully engaged, it's as if you're driving impaired. And there's so much automated that it's difficult to be so vigilant. Once the car starts braking, how much latency can I afford just assessing what caused it to slow down? How hard is it braking and how closely is traffic following me?
