Im not an engineer but from what Ive seen them write, I dont know that there was tinks.
It wasnt metal like the regular navy subs, the carbon cant flex repeatedly like the alloy on subs. The carbon seems perfectly fine one minute with no sign there are fibers breaking until it achieves failure then its just gone.
Well if there is an after life, they can boldly start out their conversations with the all famous... “There I was, minding my own business and!...” lol
My amateur view is that carbon fiber seems like the wrong material for a vessel meant to resist outside pressure rather than to contain inside pressure. That’s because the fibers would tend to be under compression rather than tension, which doesn’t seem to play to their strength so to speak. Don’t know if that’s a valid analysis but it’s what comes to mind first.