Could be like the 007 movie, Tomorrow Never Dies? Maybe someone hacked the barge’s navigation system and put them on an intercept path, lol.... But the catch is, they would need to know the Navy’s path, and that is definitely classified.
I see you're tryin' to have a little fun with me, but seriously...
The Oil/Chemical Tanker Alnic MC is more than twice the size and less than 5% as maneuverable as the McCain, and has the right of way at sea.
It would be effectively impossible for the Alnic MC to run down the McCain with or without intent, UNLESS
The McCain had a major dereliction of duty, discipline and seamanship among the Captain and several crew members, or the McCain suffered a catastrophic failure of the navigation and collision avoidance systems AND a failure of crew discipline and training in emergency response.
The Navy has just signaled a concern over the entire Navy and not just the McCain, which means they are concerned over similar EQUIPMENT on other US Naval ships.