Drivers often do not follow rules of the road (changing lanes in intersection, turning across double yellow, running red light, squeezing a turn in at a red light, etc), which makes full self driving challenging. Fault on truck for changing lane at improper location and not signaling, but fault on Tesla for not manually stopping. You're both at fault. I think all manually driving car drivers would have stopped, honked, get pissed off, let it go, continue on their day. It's like driving down the road, and someone decides to make a left turn out of a parking lot but made a bad decision and started turning too late, and you see that you will hit them because they won't make the turn in time, but you decide to t-bone them because you have right of way even though you could have stopped.