This may have already been reported by @Tanthalas. My memory's a bit rusty about it.
After clearing the Nashkel mines, Officer Vai appears in the Jovial Jugler Inn in Beregost, and a girl named Chloe appears close to the Thunder Hammer Smithy to warn CHARNAME. If CHARNAME meets Officer Vai and receives her quest to fetch her as many bandit scalps as possible BEFORE he meets Chloe, the girl will still be there and will still address CHARNAME in the same way. There is no dialog option to tell Chloe that CHARNAME has already met Officer Vai.
Either Chloe does NOT chase CHARNAME to tell him about Officer Vai if CHARNAME has already met her, OR Chloe still chases CHARNAME (after all, if she's out there looking for him, how can she know that he met Officer Vai after she left the Jovial Jugler?) but CHARNAME gets a dialog option to let Chloe know he has already met Officer Vai.