It's intentional game design.
When a "Lead" (Piste in french) is declared on a prompt, it means following it will disrupt the current story (well, in fact, the current deck). Following a Lead is a strong move by the player (and one of the only ones available in the game). When you follow a Lead, you explicitely say to the game : "I want this theme to be added to the story".
I would gladely read/play a game where this notion is twisted.