The car can’t move without trajectory calculations though.
If the car ahead of you pulls forward when the light goes green, your car can start moving forward as well keeping in mind the lead cars trajectory and speed.
If it was just don’t hit an object in its path, the car wouldn’t move forward until the lead was half way down the block.
The car knew the truck was there in this case, it wasn’t a failure to detect. Due to a programming failure it thought it was safe to move because the truck wouldn’t be there.
If you’re following a vehicle with proper distance and it slams the brakes you should be able to stop in time as you’ve calculated their trajectory and a safe speed behind. But if that same vehicle slams on the brakes and goes into reverse, well… Goodluck.
It’s all assumptions assuming the detection is accurate in the first place.