From the BBC's web-site:
Pilots have already hit back at the early Swiss move to blame the Russian pilot.
"It seems incorrect to me for Swiss air traffic control to be already publicly blaming the Russian pilot 'because he did not respond to calls'," said one contributor to the Professional Pilots' Rumour Network.
"Why did they not co-ordinate this action with the DHL aircraft?"
Others said pilot fatigue and language problems might prove key.
"Tragedies like this are caused by governments and authorities not addressing the problems we encounter every day," one writer added.
Perhaps it's time for condolences and reflection rather than theorising...