My educated (a little bit of engineering at uni) perspective is: Completely idiotic to build a submarine out of carbon and not have the means for a complete inspection for manufacturing defects as the original article suggests.

Carbon, as you correctly note, needs to be very homogeneous. Bubbles, lamination defects or -god beware- fissures lead to failure, of the sudden, unannounced and total kind. And not only is it necessary to check after production, but also after regular short intervals of use, because a mere scratch in the carbon can be fatal.