Perhaps, heaven forbid, the jurors looked at the evidence.
It's weak against the woman driver in particular.
She is alleged to have clipped the cyclist, or possibly his bike, with her door mirror.
He fell to the ground and was run over, twice, by following drivers.
Even if you accept the woman is entirely culpable for knocking the cyclist off his bike, it seems a stretch to me to find her responsible for his death.
The evidence against the van driver looks stronger, but given there was another vehicle known to have hit the cyclist, it may be the jury thought they couldn't rule out the possibility of a third - it's not clear how long the cyclist was lying in the road.
The decision suggests the jury could not be satisfied so that they were sure it was the van driver whose vehicle killed the cyclist.
It may the jurors said: "He killed him right enough, but that could be one of us next week so not guilty."
But I doubt all 12 would have agreed on that, even if one or two might have thought it.