SAS's pic shows one of the building's aircon units (behind the tail) pushed sideways off it's fitting. Look at the other unit on the right and compare the feed pipe to see how it has been moved.
The picture also shows a masonry wall at the back of the hole the helicopter fell through.
Perhaps the helicopter landed flat on the roof with a little bit of yaw causing the tail boom to strike the aircon unit, and with an unsupported roof at the front of the thin skids the machine fell through it nose first.
Only those currently investigating the scene are closer to the truth to what actually happened.