I'm sure that's right, Eddie.
Certainly they were at fault. These anti-money-laundering regulations change all the time, and brokers have a legal responsibility to report certain transactions to governmental authorities, and IB weren't on the ball about it as they should have been.
My information (though perhaps I should say "trade gossip", not "information"!) is that IB feel they were treated "very harshly", but not "unfairly" or "incorrectly", and they know they went wrong re regulatory compliance.
In view of this forum being full of spot forex traders, I just wanted to make the point that (in huge contrast to all the regulators' rulings against FXCM, for example, which have arisen over dishonesty and deception to their own customers) this was a technical, strict-liability offence NOT relevant to any retail trader thinking of using IB.