This is my bet. PNT spoofing or jamming. Maybe even directing the merchant into USN. From the looks of the frieghter's track into Fitxgerald I'd believe it.
I know zero about navy ships.
But I have a question.
How can a US Navy Fighting ship which has all kinds of radar for battle purposes and devices that can locate submarines, manage to collide with a ship that is making no effort to hide?
The top officers of the Fitzgerald have already been relieved of duty and their careers are ended in the US Navy. I suspect others will follow.
This crew should have been extra careful as a result of the first accident. They should be in prison.
Well, that's one way to render your four billion dollar aircraft carrier irrelevant. Just steer it right into the path of some supersonic, nuclear tipped drones and there it is.