I hate that “confirmation bias” have become moo words with people nowadays.
The logic is pretty sound:
A company that does business in the United States must comply with American laws.
It is forbidden under American law for a company that operates from the United States to do business with Iran.
The company, through its child, shipped oil from Iran.
American authorities, enforcing American law, ordered the company to divert the ship and turn over the oil for confiscation because the shipment was illegal.
Oil is confiscated.
I remark that sanctions do not require the approval of the United Nations. Under customary international law, it is an application of sovereign authority. Any country can apply sanctions and can do so in any way you like. What the USA has said is that “if you want to do business here, we forbid you from doing business with Iran”.