OK the link I read said that the child's mother had been found, that he had been being looked after by his aunt and 'no one knows how the mix-up happened'. Doesn't this suggest that the boy got out of the house while his aunt thought he was asleep or something? And may not even have been missing for very long? When my brother was 2 he got out of our house and walked round to his grandparents (admittedly not more than a 10 minute walk) when my dad thought he was having a nap.