I didn't see the program so I can't comment specifically.
One needs to keep in mind that design philosophies and processes .. and certification requirements ... are evolving animals.
At the time of the Comet .. structural fatigue wasn't one of the top line concerns .. although it certainly became so after the early hull losses.
The Brits did the honourable thing and let everyone in on their investigation processes and results ... Boeing took the benefits to heart ... with dreadful commercial consequences for the UK industry ...