Hi,
It is my belief that Boeing aircraft are more heavily constructed than the certification requirements dictate ...
It is also within the boundaries of good manufacturing practice that when a hull is exposed to excessive "G" (crash) that there is a regularity to the fractures ... that would be considered at the design stage, similar to the expected deformity of a car after impact.
Interesting comment .. but nothing to do with the documentary points.
I suppose you don't seen the documentary for post such comment.