Three also made it plain last week that all she has that makes her valuable is information. That, and that alone, is what is keeping her alive. If you ask me, she simply lied for the benefit of her audience. If she can keep them believing that there's one Cylon somewhere else, then they'll keep her alive. It doesn't matter where the final Cylon is, whether with Cavil and his crew, on her basestar, or on Galactica. All that matters is what the people she doesn't trust believe. Simply put, don't believe everything she says.