What is the likelihood this assailant thought the child was his own - maybe if he had been manipulated by voices?
Most likely this could have been an act to abuse the child sexually. But the news seemed to not mention this.
Under voices 'anything' is possible - but the strain to abduct this child and not talk really is concerning and seems to be that this was the act of a man who wanted to abuse the boy.
It seems very likely that the story about thinking it was his child would be used in thought-out circumstance for when caught. Stating 'he thought the child was his daughter' - seemingly organised to seem like it was mental health, to show he was of ill-mind, the differentiating between being a girl when it was a boy for maximum impact in mental terms. (organised differentiating)
The +ABC :
It all seems a bit unlikely and thought-out. The fact he was in a night-gown might of been a sign he was in a sexualised state as well. (impacting on self-being, feeling sexualised, exposed privacy)
This will have somewhat lasting consequences for the young boy, trust and much more.
We wish him well in his recovery.