I agree with most of you guys. Specially with the "holes" listed by double bogey.
But we shouldn't forget that the ultimate cause of the accident is the failure of the crew in changing the heading of the aircraft. They KNEW they had an obstacle just in from of them up to 15 seconds before the crash.
The CVR suggests that the copilot received the command to change the course and used his control knob. But the helicopter didn't change its course, as the graphic shows. Why? Perhaps the AP mode selected. What do you think about this?