From what I can discern from the article the car just pulled over in front of the truck and stopped.
My son drives 18 wheelers, coast to coast.
You wouldnt even beleive some of the stories he tells about stuff like this.
You have no knowledge of which you speak. None.
Have you read the police report? No.
Have you driven a tractor propelling tons of weight? No.
Having said that, may God be with those that perished, with the driver of the tractor and his family.
the mother stopped and parked her car on a highway lane and did not pull over to the shoulder, it's impossible for any drive to judge that a car is stopped in a lane, let alone, stop in time.
It's just not always possible to keep the correct distance around here. You can have the needed space and other drivers will pull in and often slow down or even hit their brakes.