In season 3, Juliet is told that her sister would die of cancer if she left the island, but Jacob would heal her if she stayed. Obviously, Ben is a manipulative bastard, so he probably was lying (especially when you consider his lack of communion with Jacob and his eventual lack of faith). But it does seem to parallel in some ways Dogen's story. Dogen was supposed to go to the island with the promise that Jacob would heal his son and he could never leave (or heal his son). The difference was that Jacob personally visited him.
I'm not saying that Juliet's situation could be real too. I think the weight of the evidence is that Ben made it up. But it's quite possible that Ben knew of Dogen's story and decided to recreate it for his deception (the best fraud has to resemble the truth). No way to know for sure, though, unless we hear what Ben has to say about Dogen (if he says anything, which I hope he does, since he clearly knew about the Temple back in season 3).
I'm not saying that Juliet's situation could be real too. I think the weight of the evidence is that Ben made it up. But it's quite possible that Ben knew of Dogen's story and decided to recreate it for his deception (the best fraud has to resemble the truth). No way to know for sure, though, unless we hear what Ben has to say about Dogen (if he says anything, which I hope he does, since he clearly knew about the Temple back in season 3).