Entering via the bedroom window would have left a forensic 'footprint' and possibly actual footprints or scuff marks. No such marks were ever found rendering the theory that someone climbed in through the children's bedroom window somewhat unlikely.
I also think it is very unlikely. The window is too narrow and although it looks fairly low from inside the room, the cill is quite high from outside. I dont think it is pheasible tbh.
I dont think any human went through that window.
- Maybe it was an escape route, that someone could have scrambled through and virtually fallen out of ?
- Maybe to pass things to the lifter of Madeleine ?
- Maybe to give moral support, instructions and to warn of anyone coming?
- Maybe to give the false impression that Madeleine had herself exited via that window?
- Maybe to give a possible abductor time to get away, cos everyone would have been searching in the wrong places. i.e. places where Madeleine would likely have gone, rather than places an abductor might have gone?
- Maybe to exhaust any fumes from the room if certain drugs were used, like chloroform ?
There were other things that I thought of, but I can't remember them now.
I think the window thing is a red herring by the abductors, anxious to hide their actual route and delay the search