I dont know the full story here.
But seems like more proof that its not worth the hassle of driving a truck on UK roads.
From the very limited information I read on the news article it seems like the sprinter van was up the truckers arse. When the HGV applied his breaks said van went into the truckers arse without any lube.
Moral of the story either use lube or keep a respectable breaking distance away from the vehicle in front.
*I could be completly wrong but I am just guessing as to what happened.