TR,
I think your opinion is valid. After well over an hour airborne at night, the crews' eyes should have been as adapted to the dark as they can get. The scattered light from the surrounding street lamps should have been very helpful in judging the distance to the ground. The location of the street lamps, and building lights should also have given potentially good sense of visual flow as the ground neared, in the helpful context of diffuse background light.
From the wreckage photos, I suspect that the aircraft "dropped" from at least many tens, and possibly hundreds, of feet. Perhaps compare the wreckage of the Norwegian air ambulance that looks like it fell about 200 feet.