If you seriously think that a U.S. warship could be deliberately rammed by a supertanker in a "terrorist" attack - you need to do a serious re-think.
 
The USS John McCain is a modern destroyer with a top speed over 30 knots.    It can accelerate and turn very quickly.     Furthermore, it has radar and defence systems which would identify and track any other vessel within missile striking range and beyond.

I have no doubt that this was a drill gone bad.