This is the point i really do not believe. The housing of an engine is built to keep debris away from the plane. Look at Videos where they cause katastrophic damage to the engine to test the housing. Even if it's an "old" housuing (parts of plane have reular maintenance, so actulally no part of a plane is really old) i have difficulties to buy this story.
When pressure delta was so high that she was sucked out of the window, the plane was high and fast (about 1000km/h ?).
Does the debris have a chance to move towards the plane at this speed?
I dont know. I am not a physicfag or a planefag or a pilotfag.
And please prove me wrong if my assumption isnt't right.
I am just thinking out loud.