I fly out of DR quite ofter and that outfit is pretty much par for the course. The more interesting thing to know (which we never will) is how many other incidents this FA has had and whether the Captain was informed and got involved or choose not to.
edited to add: The apology being quoted on one of the blogs is pretty much a complete admission of racial bias.
The apology, and refund, appear fitting.
I pity those who think race is some sort of "card" to be played when advantageous, and not a state of being that people deal with on a daily basis.