I don't know if this is what is being referred to but I assume it is;
he noted that the children's bedroom door was not ajar as he had left it but half-way open, which he thought strange....
http://www.mccannpjfiles.co.uk/PJ/GERRY-MCCANN-10MAY.htmKate says;
in England Madeleine sometimes woke up during the night, around 2 ' 2:30 AM and went to her parents.
http://www.mccannpjfiles.co.uk/PJ/KATE-MCCANN_ARGUIDO.htmIf any of the children had been liable to wake up early evening then it wouldn't have made sense to go to dinner and leave the children alone, would it? Even so, it's Gerry's first thought after noticing the open door;
having then put together the thought of MADELEINE having got up to go to sleep in his bedroom so as to avoid the noise produced [created] by her siblings.
http://www.mccannpjfiles.co.uk/PJ/GERRY-MCCANN-10MAY.htmHe checks all three and all three are sleeping peacefully. So it seems it wasn't Madeleine who opened the door, so how did it move? Gerry, like his daughter, 'moves on'. He asks a question, fails to get an answer and drops the subject. He visits the bathroom and leaves the apartment. The strange case of the moving door is forgotten, it seems.
Having brought up three children my thought would have been that Madeleine had visited the bathroom. My children did that and scampered back to bed afterwards. We haven't been told whether she ever did that, and her father doesn't seem to consider that possibility.