Descent Angle
I have restricted my comments to the building structure and local area as thats all I know, but if you professionals look at the photographs, which show the flue on the roof, the remaining AC unit and the street lighting columns, by my reckoning the helicopter in the last 20 metres (or higher) was descending at an angle of between 45 and 90 degrees, if it was not, it would have damaged or destroyed some of these obstructions. I dont know whether this gives you something to look into or not.
PS I am not a journalist.