If this article from the AP is right, it looks like both sides are looking to ease down from this.
Iran has realized that they really overstepped here, and the Brits are realizing there's not much they can do. So both sides really have an interest in backing off here.
In essence, the Iranians found they had a much weaker hand. And if they were to start something in Iraq, it would probably force the Democrats in Congress to end their withdrawal plans.