I'm actually kinda surprised anyone was willing to be the other end of that transaction. Why would anyone swap your bolivar for bitcoin when you're doing it because you know the bolivar will soon be worth a lot less?
As far as I know, it's not how it works. They essentially swapped USD for BTC.
When the currency is crashing down like that, people try to discard it by bying something else (goods or other currencies). As I get it, exchanges were limited, so those who had better access to foreign currencies used this as an opportunity and provided services to those who weren't.
Think about remittances. One side wants Bolivars because their family is sending them money to live. The official exchange rate is dictated by the country and is a flat out lie. It is an illegal transaction, but not an immoral one.
When the currency is crashing down like that, people try to discard it by bying something else (goods or other currencies). As I get it, exchanges were limited, so those who had better access to foreign currencies used this as an opportunity and provided services to those who weren't.