If a country like the US imposes sanctions on a country which includes, quite prominently, restrictions on investment and financial activities, and afterwards you go out of your way to provide assistance on how to circumvent those restrictions on investment and financial activities... Where's the surprise that your assistance gets you in jail?
I should point out that there is nothing vague about sactions.
https://en.wikipedia.org/wiki/Sanctions_against_North_Korea
If a country like the US imposes sanctions on a country which includes, quite prominently, restrictions on investment and financial activities, and afterwards you go out of your way to provide assistance on how to circumvent those restrictions on investment and financial activities... Where's the surprise that your assistance gets you in jail?