Film director James Cameron has expertise in designing and testing these submersibles, and he has many criticisms of the design of the sub that imploded, and of the hubris of the CEO who ignored repeated safety warnings from the diving community. He also mentions that the sub seems to have been attempting to resurface when it imploded, suggesting that they were aware the hull was starting to fail.
If you read the Wikipedia entry on the Titan submersible, it mentions somewhere that the original designer only intended it as a one time use vehicle. That doesn’t inspire confidence.
That is freaking insane! So they knew this wasn’t meant for repeated dives and did it anyway……