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.
It also would’ve stayed up a lot longer if the watertight compartments had gone all the way up, so water couldn’t have continued filling ones further aft. It still had more compromised than it could withstand, but it may have been able to remain afloat long enough for the Carpathia to arrive for rescue