I was in my introductory history class, and I asked my professor why the map showed that Haiti was still a French colony after the war, and she didn't know the answer. It just seems kind of weird to let them have it when the British could have easily squashed any remaining resistance and wipe out France in the Americas completely.
Haiti was the richest of the French colonies at the time. It was much more profitable than the colonies on the NA continent. France would have spent more resources to defend it.