Either that or she was told to say that because no one on her staff realized it would be criminally negligent for her to announce to the entire world.
If you read the Podesta emails it is clear that Hillary’s staff (especially at the mid and high levels) are very attuned to DC culture and know exactly what security classifications mean.
They spend many many hours discussing what she should and should not say on a wide variety of topics, whether at debates or in interviews or in any other public setting.
Imho there is zero chance they would have authorized that statement.
If any staffer had suggested it they would have laughed out of the room—if not fired on the spot by Podesta.