What's the matter Baz? Dog came off the "sidewalk" and bit you?

It looks strongly as if the boats knew where they were, so the only argument that they were in Iranian water would be an unexpected location of the border, if I may put it like that. That strongly hints at an Iranian intention to provoke.

Next unanswered questions - where was the Cornwall? Where were the Iranian vessels that got to the freighter before the Cornwall did? Why did no-one see them coming?

The argument that the Cornwall and other shipping should have stayed off any water the Iranians could conceivably have taken a fancy to is unacceptable for it is a licence for territorial aggression.