Is that the toilet seat seen spinning along the road?
to be be fair the truck was far too close to the scumbox so yes the truck driver carries some blame.
A 4 second gap for a loaded truck in good conditions is the minimum a truck travelling at 56mph is travelling just over 82 feet per second the truck was way too close the reaction time of a fit alert driver is an average of 0.7 seconds the drivers reaction time in this case was around the average if not a little above, the problem is the distance between him and the scumbox.
■■■■ poor driving by all concerned.