Earlier quoted context omitted.
Do include the next part aswell: "Griffith was denied permission to travel to North Korea by the State Department but decided to attend the DPRK Cryptocurrency Conference anyway."
It's not okay that he should need permission for such a thing I don't think.
It may have just been a talk, but a talk is a service, and he knew it was a serious federal crime.
If he planned to rely on the "It was all public information anyway" argument, he is a fool.