When it comes to sequences of bad decisions leading to disaster, "nothing could be done" is always the end of the story, not the beginning. When a mountaineer is trapped on a high Himalayan summit, too cold to move and out of oxygen, in bad weather with no rescue possible, one doesn't ask why nothing could be done at that point. The question is how that situation came about to begin with, and what could and should have been done earlier, when there were still options, before the scenario became lethal.
The decision (by, in this case, governments) to permit vessels configured for coastal waters to be used as open-water ferries; the poor maintenance of the vessel; the decision by the command crew to sail that vessel into a storm with an unbalanced load that could not be corrected to a proper trim; the decision to sail a direct course at full speed; the decision to pay minimal heed to warning signs of trouble -- those are the irresponsible decisions that doomed the ship and most of the passengers and crew. Even if there was sabotage, for which there is no evidence whatsoever, it was entirely unnecessary under the circumstances. Sabotage didn't cause the command crew to steer a weak unbalanced leaky vessel directly into storm waves at full speed without adequate watch below decks. Any sabotage that could have occurred after those negligent decisions led to inevitable crisis was irrelevant, like sending an assassin to murder the alpinist who's already trapped and freezing on a high summit due to pressing his luck much too far. (And just as impractical to carry out, as well.)
When I started following this thread, I was quite content to assume that the sinking was a tragic accident caused by completely unexpected equipment failure. "A design fault" unknown to everyone concerned. But thanks in part to your tireless efforts to throw doubt and blame around in all directions, it's become clear how the vessel was operated with depraved indifference making a disaster inevitable sooner or later. There were saboteurs on the bridge, sure enough. They were running the ship.