My Father (now retired) spent pretty much most of his Career as a Diplomat, being posted every 3 or 7 years overseas somewhere (which was good for me as from 7 yrs upwards I get to go somewhere different for my summer holidays, but that’s another story).
I seem to remember that before the introduction of an International Licence, It was required that for him to drive in another country that he would have to take a test and pass enabling him to drive in that said country (I'm going back a few years now!). As a diplomat the Embassy would apply on his behalf for a provisional licence for that country and the said State would endorse the application with a Full Driving Licence (providing he had a Full licence of his diplomatic country) some sort of Gentlemen’s agreement within the diplomat world.
All this was supposed to come to a end with the introduction of the International Licence, but for Diplomats it didn't, simply because some Countries (purely for example only, Russia, the Police would target Diplomatic Number Plate drivers, and at Gun Point would ask the drivers to produce there Papers (Passport, Dipo ID and Driving Licence, which by international law was required) and then under Russian Police Road Law would then threaten to confiscate the Driving Licence unless a fixed fine for (say) $1000 was paid, under the new International Driving Licence Rules that could feedback back to the Driver being disqualified in his own Country.
The other side of the story is that if a Diplomat gets disqualified in his own Country then he could in theory get a brand new clean licence in another country which would enable him to drive anywhere.
My bet is these guys are using this loophole for this purpose, (i.e., with the right documents).