The only way the carbon tube hasn't turned to sea dust is if the porthole failed first. When carbon fibre fails it catastrophically fails. I'd put money on the

The only way the carbon tube hasn't turned to sea dust is if the porthole failed first. When carbon fibre fails it catastrophically fails. I'd put money on the joint between the ti and carbon being the weak point and once there's a chip in the carbon under that much pressure it'll disintigrate.