justme69,
He also witnessed the MD's roll to the left followed by "an abnormal and sudden roll to the right" of the plane before it started to fall. During the fall it yawed to the right. He also says he saw some flash on the left side of the plane (i.e. around the left engine/tail area).
The ground tracks confirm the Iberia pilots observation of the plane
being in a strong slip to the right on touchdown.
Indicating strong lateral forces in play.
This just doesn't look like a "normal" plain stall to me.
XPM