Please don't post baseless accusations. I think dang has said that he tries to moderate less, not more, when YC companies are involved. (Although it's impossible to say what he would do in this situation.)
Like I said in another comment it is simpler than that. They just serve the login page/payment page to all HTTP requests. If they do that then the submission itself likely get's flagged as there is no workaround (just like if I submit my blog with a banner saying "hey you pay me $1 to read my cool post")