Not really. There is just as much danger to drivers from buses. Taking a turn across a junction like that is immesurably stupid and wreckless. Many years back I saw a bus sat on top of a car bonet where a driver made a similar mistake (the road layout as it had been is now different so unfortunately I cant show you on google streetview the viewpoint of the driver)
A car with a low seating position will not be able to see over a transit van to see oncoming cyclists, motorcyclists and yes even single decker and low profile buses. Motorised buslane users will be doing between 20-25mph on average, and with a for bit of unstoppable weight behind it. A black cab is near 1 ton in weight iirc, due to the body work, disabled access etc.
He would then be facing at the least a charge of without due care for endangering not only the other driver but many passengers. I have been on a bus that has had to take such a hard brake to avoid an idiot like this, that people flew out of the chairs. I would imagine he's facing that now.
Some people here are confusing risk mitigation with fault. The driver legally and morally is responsible for ensuring that he takes the turn safely, does not force others to deviate or brake, or collide with them. Rule 180 of the Highway Code covers this. So do other aspects of it.
People are just human beings. Gaz, the same as any other rider (whether thats me, you BB, Lee or just that bloke you often see out and about) is never going to have avoided that, all the more reason for a driver to take care in adverse conditions - the cold, dark and wet is distracting enough to drivers, let alone some cyclists.
Even if the van driver has flashed him out, it is still the responsibility of the driver who wishes to turn to make sure that it is safe to proceed. The responsibility does not pass on to the van driver, the van driver is meerly indicating to the other that "I wont advance, you can attempt a turn if you wish."
There is no insurance firm on the planet that would professionally assess that as 50/50. They may try their luck, but they know where fault lies.