The live leak video showed the bird spinning before impact - that is because the tail rotor is missing. What few pictures there were, the tail rotor mast was separated from the main wreckage by quite some distance, which indicates that it separated from the helicopter in flight.
That video has been labeled as false footage by other internet resources. That parts of the chopper were largely separated from the main crash site does not in and of itself mean they separated in flight.
For what it's worth, CFIT is not an instantaneous departure from life. Clouds and fog are one and the same, the crew will see terrain before they impact, and react to it. Passengers may or may not see what is happening, but they will be aware of the pilot's attempt at corrective action and experience initial impact and likely the resulting gyrations. Not saying it isn't quick, but they are aware of their looming departure.
How would I know? Because I've background in aircraft accident investigations and with specificity, this type of accident. Got to pick thru the pieces of the puzzle for one of my roommates in '71 among others. Their flight path prior to final impact was typical and reflects that a) they saw the mountain at the last moment and b) tried to climb without success. The impact trail thru the trees reflected about 100' of climb before the main rotor was demolished and led to a smoking hole in the mountain side.
Question was asked earlier as to why the pilot didn't hover for a bit rather than continue flying? Fair question on one part, but in general terms hovering out of ground effect (close to ground) is not a brilliant strategy for choppers. OTOH, flying at greatly reduced speed, say 20-25 knots is viable and an approach we used in the mountains of Nam many times....successfully. Tree top to tree top in the fog works. It works better here in the USA because nobody it likely to be shooting at you while doing such silly things.
