There is absolutely no evidence that a group of Haitian revolutionaries performed a ceremony directed toward the Devil, much less making a pact with such a being for success in their revolution.
Recent Voicing of the RumorOn January 13, 2010, in the wake of a massive earthquake in Haiti, Christian Evangelist Pat Robertson publicly stated that 200 years ago Haitians "got together and swore a pact to the devil. They said, 'We will serve you if you will get us free from the French.' True story. And so, the devil said, 'OK, it's a deal.'" Robertson continued by stating that Haiti has been "cursed by one thing after the other" since this pact was formed.
The statement was widely interpreted to mean that the 2010 earthquake was a direct result of this demonic pact made 200 years ago. People have often paraphrased Robertson's statements to say that the earthquake was specifically God's punishment toward the Haitians for the demonic pact.
Origin of the RumorThe rumor refers back to a purported ceremony held at Bois Caiman in 1791 on the eve of a major uprising. The actual ceremony was a Vodou ceremony dedicated to Petro lwa, which are destructive and angry spirits who originated in the rage of brutally treated Haitian slaves.
Vodou was a powerful revolutionary force. The white colonists were eager to demonize anything associated with Vodou, and even black leaders who rose to prominence after the successful rebellion subjugated Vodou both to gain credibility among white nations and to keep people away from the potentially revolutionary forces that simmered at Vodou ceremonies.
Comparison with Demonic PactsThere is no evidence that suggests the Bois Caiman ceremony, if it occurred at all, was anything other than a Vodou ritual. Followers of Vodou see themselves is a fairly close-knit relationship with the lwa, as they are the beings that affect their daily lives. They are already serving the lwa (as well as Bondye, the good god of all). No specific new pledge would be needed.
Moreover, the Petro lwa are not demons, much less the Devil himself. All lwa, even the angry Petro lwa, descend from Bondye and exert his will upon the earth.
Notions of good and evil within Vodou have to do with things that are in concert with Bondye's will versus those that are contrary. Treatment of Haitian slaves was so brutal that they often died within months of reaching Haiti. The only way of saving those lives was rebellion, and thus rebellion was seen by Haitian slaves as the will of Bondye. The invocation of a Petro lwa was simply a request for additional help from an appropriate spirit.