Litebulbs,
Well I'm hoping a sheet metal mechanic who repairs these things will jump in here and comment. I'm not an expert at anything. Just a has-been. ULD's (Underfloor Loading Devices?) are clanky affairs with poorly fitting thin coke "can" doors on the sides that sometimes blow apart on the ramp just from jet blast and high wind. They have imprecise hinges/curtains etc and are just designed to keep dust off or to keep the customer's contents from shifting. They would just simply blow apart save the frame and the steel bottom which appears as that tin colored "strap" in the photo. (It's amazing to me how golf nuts seem to see putters and golfbags everywhere they go
)
A pallet buildup however would have plastic, netting, straps etc and may be what we're seeing here. But in the torn open region; under this missing faring area, IIRC is a pneumatics crossover bay and should not have anything like this in here. Thus our deduction that it got there through the aft wall of the cargo compartment, which is what you'd expect to see if the spars and stringers failed as forensically described by the engineers in previous posts.
But I am no expert. The above post is; as all my post are: my opinions only. I could be wrong about everything; I'm old.
pac - out