Its almost never correct to rip on a project from a distance. Only two things can happen, one, you are wrong, and the project succeeds. This is a personal catastrophe for your career at that company. Two, you are correct and the project fails. Its rare this will get you enough credibility to make the risk worth it. There are always others that will show up and dogpile as if they "knew" the entire time themselves. You need to be consistently correct about failure to get truly noticed, but then it asks a lot of questions. Why are you still working there? Why don't you have enough influence to prevent it in the first place? "I told you so" rarely accomplishes anything good.