With Haiti, you don't have to go all the way back to the settling of the island for brutality. The closest analogue I've read to the behavior of the French who ruled Haiti was the treatment of camp inmates by the Nazis. Haiti was the worst colony in the Caribbean. It made the antebellum South look like a utopia in comparison. The life expectancy for slaves sent to Haiti was abysmal. Most of them died on the plantations within about 10 years of stepping on the island. So many died that in order to sustain the slave population, the French had to import tens of thousands every year. They wanted to create a native slave population, but it didn't work because they worked the slave women so hard that they made them infertile. They ruled by means of terror. The stories are sickening. They executed disobedient slaves by stuffing their rectums with gunpowder and blowing them up. They strapped them down and poured boiling cane sugar over their heads. They buried them up to their necks and smeared them with honey so that they'd be eaten by insects. For punishment, they cut off their slaves' limbs and poured hot wax on the stumps. This had gone on for a century prior to the revolution. By that time, there were about 500,000 slaves being ruled over by 30,000 whites (as well as, partially, 40,000 mixed-race Haitians).

It was not smart or good for Dessalines to massacre the 4000 or so whites that he did, but that act is so minor in comparison with the horror that the French visited on Haiti for 100 years that it's barely worth talking about.