Flying Frog- post #80.
If Mrs Manchester did hear a loud bang 20 mins. out of LHR, this could have been the first piece of structure failing.
The remaining structure could then have held together for the 12 hour flight to Hong Kong (1 pressure cycle) and then failed on the next flight when the cabin diff built up towards max.
This failure would mean that the "fail Safe" load paths "Failed"!
However other design features appear to have worked. "Tear Stoppers" to limit the progression of splits in the A/C skin.
Just my thoughts from 39 years in aviation engineering.