Seems to me there are a few things about this that people have failed to consider.
One thing is that the driver’s tachometer record would have recorded his speed at the time of the incident, which would certainly have been taken into account at the time. This would partly have been used to decide his liability for prosecution or not (40mph for LGV’s on single carriageways; unless a speed limit indicates less).
With air-ride suspension (now usual) if a 44tonne vehicle comes up behind you on a fairly good road surface, while easing off on the power – it will be so quiet you may well not hear it.
For me it brings to mind the death of the son of a close friend of mine; he was killed in a similar incident, he was 12yrs, he had been specifically forbidden on this specific occasion to go on the main road with his bike as had his friends. The lorry in front stopped (he used his mirrors) the lorry that did it stopped (tacho recording 33mph-on a 40mph road) the lorry behind stopped, the car coming the other way stopped, his two friends on bicycles behind him stopped, – they all saw it. He went under the truck.
He turned across the road without looking, to go through a field gate.
What can any driver do if someone comes immediately in front of them without looking?
We (my friend {the father} his older son and mother) went to see the driver (very local), a while after we had buried the lad, to try and reconcile him to the fact that it was not especially his fault, that he may a few weeks before have even been the man who delivered the bicycle.
The real difficulty as it seems to me, is that we all demand cheap quick easy transport and will not properly recognise the consequences of obtaining it.