I also read (unconfirmed) that the tesla vehicle accelerated in the last few seconds. It couldn't see the truck and thought it had open road. That might speak to the optics systems.
Really tho, anything you say could be said in abundance with any younger driver, or any distracted driver (tired driver, driver arguing with passengers, driver glancing at cell phone after it beeped, eating driver who just dropped something in their lap): "you don't know what their capabilities are or how they might react or what dangers they potentially pose".
The thing is, once a tesla makes a mistake and they figure out why, after the next update, no other tesla will make that mistake again.
Automated cars will only get better (and fairly quickly) until their accident rate is vanishingly small compared to human drivers.
I had a friend who was nearly killed (months of therapy) after a driver behind her dropped their cell phone on the floor and bent over to pick it up and so plowed into her from behind so hard that the rear passenger seats were sandwiched into the driver seats (anyone in the rear would have been killed).
Humans mistake rate is known and will continue. Autonomous drivers is unknown and will get better.
At some point, insurance for autonomous cars will be substantially cheaper than for human drivers.