In general, sanctions are notoriously complicated ( sometimes with seemingly -- or actually -- contradictory notes ). And just to complicate it even further, it

In general, sanctions are notoriously complicated ( sometimes with seemingly -- or actually -- contradictory notes ). And just to complicate it even further, it uses a system of waivers ( licenses ), which allow you to ask OFAC to engage in some ( usually explicitly listed ) of the otherwise prohibited activity. Due to their size and reach, it is not unlikely that both entities secured such a license. Naturally, there is a compliance cost that they incur as a result, but I am sure there is an interest in US government to keep those lines of communications open for one reason or another.