FACT CHECK: Obama Bribed Iran $400 Million to Release U.S. Prisoners?

This report on Snopes https://www.snopes.com/fact-check/obama-bribed-iran-400-million-to-release-u-s-prisoners/ has had me chuckling away today:

'It is true the U.S. agreed to the settlement at the same time it was negotiating a nuclear deal with Iran and for the return of four U.S. citizens who had been detained by Iran. However, the negotiations over these these issues were conducted by completely separate teams in order to avoid any overlap or suggestions of connections between them.

... 

The fact that the money was physically sent to Iran in various currencies  rather than simply transferred by wire may seem odd in the context of the United States' increasingly cashless society, but that was done in order to avoid existing Treasury Department sanctions that banned the use of American currency in transactions with Iran, and international sanctions which at that time kept Iran from accessing the global financial markets (and which were lifted in January 2016).'

Hysterical... 

Also if the money was paid in cash so as to' avoid existing Treasury Department sanctions', wasn't that illegal?