The ground/runway seems remarkably intact from the helicopter film. Is this normal and my expectation is wrong or does this suggest some breakup prior to impact (of the then smaller lower energy sections)
I din't see any helicopter film that would seem to be of sufficient quality and coverage to arrive at conclusion whether there was a crater or not. But there is also a video available that shows aircraft hitting ground pretty much intact - you can recognize all 3 lights (in triangular fashion) and aircraft at high bank. Also for mid-air break up to occur aircraft needs sufficient altitude for that to occur. Mid-air break ups do happen occasionally - usually when aircraft falls down uncontrollably for tens of thousands of feet (say emerging from an icing event or CB) but there is zero indication here that any mid air break up took place and like I said the available video contradicts it.