Dealing with elevators frequently in my line of work, I'm told by the technicians of the safety mechanism that are put in place in order to stop lift accidents from occurring..., by way of literally stopping the lift. Usually there are 4 safety mechanism that would kick in if and when a lift sensor picks up something unusual, like for example a tape or a cloth that is placed in the path of the elevator door.
It is understandable that whenever a lift accident does occur, the victim is often one working on that lift. Either through disabling certain safety mechanism, or overriding something. It's very unfortunate what occurred on that ship.
Thank you for bringing this to our attention Adrian.