Colin McKenzie ) gurgled happily, sounding much
like they were saying :

The cyclists died because of their stupid manouvre.

The penalty is appropriate, is it?

They obviously thought the risk worth taking, bearing the rather obvious
price of failure in mind.

There are a lot of ways a cyclist, pedestrian, motorcyclist or animal
could end up on the nearside of a left-turning long vehicle.

No, there's precisely two.

1. The long vehicle overtakes them then turns left.
2. They undertake a long vehicle which is starting to turn left

In either case, the person who is primarily at fault is blindingly obvious.