All that’s discussed in the video. Armed with clear underwater photography, they established there was no breached keel, just compromised hatch clamps, due to wear and tear that told in a big storm, and a vent pipe that was blown off by the storm. The previous underwater photography suggested that, but was too grainy to rely on, and the families would not tolerate any suggestion of negligence by the crew. They were not negligent. The fastened all the hatch clamps. It was the clamps that failed, and the vent pipe.
There could have been negligence.
Did the hatch and vent pipe fail because of improper maintainence?
I don’t know if it did, but if so, that would be negligence.
If a particular crew member was negligent, then why wasn’t it noticed by superiors, why didn’t they inspect and test more regularly and thoroughly, why wasn’t the crew trained properly, why didn’t they address a lack of discipline or thoroughness that had crept in, why did they hire the wrong guy, etc....
When something goes wrong on a ship, there is NO avoiding accountability. If the captain didn’t know, then he should have.