Er, is it me or is the speculation on here a bit crazy?
The aircraft has hit a ridge, a typical alpine accident. There may have been 20kt winds aloft and in the mountains these can be incredibly variable and localised. As an example, yesterday on the Kleine Matterhorn and at Schwarzsee (Zermatt, not a stone's throw from the accident site) there was 73 km/h of wind. At the Gornergrat, not 3 miles away and similar height, there was 22 km/h of wind.
Occam's razor suggests we take the simplest likely explanation. He may well have been in a downdraft and may have been in a position where he was unable to turn away. This happens frequently, unfortunately. And to see how simply and quickly such a thing can happen, even without a downdraft, I am posting the chilling Cessna Bird Dog video from Colorado for those few who haven't seen it:
YouTube - Fatal Airplane Crash From Instrument Panel Mounted Camera Colorado 1984
I don't understand the compulsion to postulate that the pilot may have been doing aerobatics (in a twin, in one of the tightest, most precipitous alpine valleys you can imagine, with 4 passengers!).
???