What probably happened is she slipped and said Osama instead of Obama and tried to pass it off as a joke, "If they're going to assassinate Obama, it'd be nice if they could also take out Osama if they could."
At least, that's the best case I could make for it.
Not something that should be joked about, though. Pretty bad taste.
I doubt it's quite the assassination conspiracy some of the commenters are making it out to be, though; rather than just people talking about current events. And in an effort to try and sound clever and witty, they're not...