Sadly, I knew the person involved and we should refrain from making assumptions on what happened until the investigation has been completed and the report published.
As an aside, I'm currently involved in a working group looking at the viability of setting up and running an incident reporting system for climbing and mountaineering in the UK. It seems like a simple idea, but there are lots of potential problems to overcome. From the experience of a colleague who has provided expert testimony in many cases, it's quite common for the eventual cause of an accident to be different to that reported initially, even by reliable witnesses such as rescue teams. Their priority is dealing with the casualty, not collecting evidence for an enquiry or for lessons to be learned from.
My feeling is that if we get a system working, the most valuable learning will come from the large number of near misses that form the pyramid on top of which incidents (events which lead to no harm) and accidents (events which lead to harm) sit.
(Feel free to pull this or move to its own thread Shark if desired)