That's a very misleading comparison, even as an informal, rough comparison for the sake of argument.
Such a comparison would have to take into account the amount of human-driven cars and automated cars - not just taking a picture of a single day, but the variance over time (e.g. if today there are a thousand automated cars in operation, and yesterday there were 50, that can distort the average stats); automated cars aren't driving in certain areas/times/weather conditions whereas human-driven cars are, etc.
Automated cars may be safer, but, open snark – I hope it's not calculating its sensor data in this way — close snark.
Of course they are selling them as safe. I still think the funding to work on them is chasing big piles of money.