HC - by 'cock-up' do you mean using the rock as a WP?
Not exactly, I mean putting the aircraft on a flight path where a terrain collision was going to occur (unless last moment emergency evasive manoeuvre can save it). So not so much using the rock as a waypoint, rather flying at a rock elevation ~300' whilst being at 200'.
One of the problems with learning from this sort of accident, is that we all smugly say to ourselves (privately) that it could never happen to us. Bit like the Clutha bar accident in Glasgow. But nevertheless, these sort of accidents continue to happen, especially when there are not many safety layers to breach. People tend to believe that only other people make stupid human factors mistakes.