It always amuses me when people use hateful speech to declare that somebody else is being hateful. It's even more amusing when a preacher uses hateful language to accuse a fellow preacher of being hateful. I'll let the two ministers of the Gospel of love settle their little tiff, (a faith-based duel perhaps?) but I am concerned with the demonization that's going on here.
I know very little about Haiti and even less about the supposed curse Robertson claims it is living under, but a quick google search turned up this wonk-ish article which seems to at least validate the fact that Robertson didn't make up the story and that there really was some kind of ceremony that invoked the help of a deity other than the Judeo-Christian one.
From there it's a matter of personal opinion -- Robertson thinks Satan's power was asked for while historians like Thylefors have a perhaps more benign interpretation.
After defending Tiger Woods and Brit Hume recently, I'm just about out of defend-the-unpopular-guy cards, but I think it's a healthy thing that, unlike clergymen in some countries whose opinions are expressed privately inside the confines of a religious building, far away from open public discourse, our clerics air their opinions in public and subject themselves to the scrutiny of all Americans. When they do so they deserve to be met with reasoned opinions and not ad hominem attacks.
Robertson may be guilty of bad timing, for, just as one wouldn't come upon the scene of an overturned car with a bleeding person inside and spend precious time wondering aloud about whether alcohol consumption or texting was the cause, the kind of historic/religious analyses he engaged in is probably best conducted only after precious lives are rescued and bodies are buried.
In any event, speech deemed offensive is, as always, best answered not by trying to shut people up or shame them into silence with nasty personal attacks, but by answering with more speech of the reasoned and persuasive kind.