Fisherman
The information that you got from that gentleman is accurate, he was part of the cream of Cuban Society that departed in the early stages of the Revolution. In 1965 FC played a gambit to release internal pressure and opened the port of Camarioca for a boatlift to the US. These action resulted in the eventual creation of the Freedom Flights to Florida, this was something very structured and the refugees were screened by US Immigration prior to departure.
The Mariel boatlift was a repeat of the early Camarioca try, it was very disorganized and the Cuban Government used the occasion to unload in the US the worse elements of their population. This was a completed reversal of the early Cuban migration to the US.
So after that we were stuck with a lot of bad characters and very few were returned to Cuba.