Did not make the intention that night to fast the following day

After a man had gone to sleep [one night], the sighting of the moon for the start of Ramadhaan was [officially] announced; [This being the case] he had not made the intention that night to fast [the following day] and [as such] he woke up in the morning and did not fast [that day] since he was unaware of the [official announcement of the] sighting of the moon. So what is obligatory upon him now?

Intention for fasting

Concerning an imaam of a Hanafee masjid who mentioned to his congregation that he has a book in which it mentions – if the intention for the fasts of Ramadhaan are not made before the last appointed time for the ‘Ishaa [prayer] or [even] after it or at the time of sahoor (the pre-dawn meal), then there is no reward for his fast. So is this correct or not?