This isn't bad storytelling. We know that it's all an overblown rumour, no-one actually knows who it is and yet here is a girl claiming to be that racer. Good plot hook.
"Let me get this straight: I, the wizard, am all alone with enemies that do more critical damage in one attack than even the tank has HP to resist... and we only found this out because the rest of the party's already fled or dead." *player glares at GM* "Where the hell did you learn how to play...