Already answered. There's no way he could have 'known' the children were alone because previously adults had remained in the apartments (Sunday, Tuesday and Wednesday). Did he really watch 5A from 5.30om to 9.45 pm?
That's the only way he could deduce that no baby-sitter was in there. Did he pick Madeleine up and then squeeze between those cots to open the window, or open it first then pick her up?
If Madeleine McCann had been noticed by a potential abductor all he had to know is ...
- where she was staying
- which room in the apartment she was sleeping in
It is indisputable that in the environs of Luz and within Luz itself, it is perfectly possible for an intruder to enter premises occupied by children while adults are in attendance and exit those premises unobserved by the adults ~ with perhaps one exception when an adult disturbed and chased the intruder from the premises.
The presence or not of adults within the accommodation was no impediment to the intruder.
It is also indisputable that it was commonplace for Mark Warner apartments in the resort to be entered illicitly by intruders ~ two within the McCann apartment block in the weeks preceding Madeleine's disappearance.
There are no reports that as a result of these intrusions damage occurred to doors or windows of the apartments which had been raided.
The files are naked with regard to these compelling investigative opportunities. Is it any wonder there is no evidence about what happened to Madeleine if that is an example of the lack of expertise of the investigators?