This situation itself is pretty straightforward, Hastert was clearly structuring, and, odds are, the person he sent the money to didn't pay taxes on the money he got from Hastert, which itself is a crime, and finally, he lied about it to the FBI, also a crime. So, three clear crimes here, one of which committed by a third party.

So many things in life are "grey" - this one is pretty straightforward, and Hastert would have known that what he was doing was wrong. The news coming out today strongly suggests that he had a good incentive to commit these crimes to hide evidence of even greater wrongdoing.