Sanctions would be pretty pointless if anyone could just go and offer goods and services to a sanctioned country regardless.

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.

Yeah, Dennis Rodman had no problem to travel there... but he probably doesn't know much that can help NK agents to break into crypto infrastructure.