I thought I had already responded to this yesterday.
So at the risk of repeating myself so apologies if this is the case.....
This could go what is called split liability (50/50)
The reason for this is that given the nature of the road, the courts would argue that both parties should have driven at a speed suitable for the drivers to stop within the distance they can see to be clear. This obviously was not the case.
The second point or argument that will be used is that both drivers given the nature of the road should have based driving plans based on what they could see, what they couldn't see and the circumstances they could reasonably expect to develop, and it would be reasonable to expect to be confronted by a vehicle travelling in the opposite direction, and so this likelihood should have been anticipated.
This is observation is obviously made without the benefit of photo's or a description of the crash scene, but by and large they are the rules the insurers and legal bods tend to apply, hence why I think it will probably go 50/50.