Sorry to tell you that it's a preventable accident. If you get some hotdog cutting you off and do not take your foot off of the accelerator then they will rule against the driver of the tractor. The driver of the BMW will get a citation for reckless driving and will have to pay for the damages to the tractor but the driver will still be culpable for improper driving as well.
Always turn the sound off so that they can't hear the accelerator.
Car brakes at 1:27sec.
Truck can be heard braking at 1:28sec.
Collusion happens at end of 129sec.
Truck can also be seen decelerating before hitting the car, all you have to do is watch the top of the screen and pay attention to the clouds, the screen dips down at the beginning of 1:29sec or just after hearing the braking sound (a sign that the truck has lifted off the accelerator/braked).