The latest non-smoking gun : Video depicting Iran navy removing an un-exploded mine from the affected ship.
The point? They were trying to hide their involvement by removing the evidence.
Or maybe not. News suggested Iran was rescuing the crew. And before rescue, what would you do? Remove any un-exploded mine from the ship. Otherwise it's dangerous for the rescue operation to proceed. And USA navy probably would have done the same.
More info needed before concluding.