The pitch angle of the a/c was seen to increase beyond even what we normally witness until it could only be described as extreme.. the left wing was then seen to dip slightly before the role was countered followed by a role to the right causing the right wing to drop.
Looking at the youtube clip (that does not have the graphics on screen which obscure the first 5 seconds) it appears to me that the right wing dropped ahead of the above description. Note that windscreens can distort the image and create subtle anomalies.
RAW FOOTAGE National Airlines 747-400 Plane Crash - Apr 29, 2013 - YouTube
What was the rate of descent on impact?