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.
That’s justification for a negligence claim. Staying that your sub meets or exceeds a standard and knowing the view port wasn’t certified to those depths is the very definition of negligence. And then knowing the vessel was only a single use and using multiple times seems like a really good claim on manslaughter. Rush is lucky he’s dead.