The bedroom window escape route doesn't seem very likely to me if the blind was down (which it appears to be in the photo).

I have just read Sadie's post and agree with what she says; although we can only speculate because there seems to be no information at all about that bedroom outer door.
From the reference below to “one patio door” and “(the other) patio door” I think the technician certainly checked it for fingerprints at the time.
I was sure I had read that a palm print was recovered from there and was later found to be that of a police officer; I may be mistaken in that unless someone can say differently (maybe pegasus can help to prove me right or wrong) as I can only find reference to one fingerprint identified as being from a GNR officer.
If the outer shutter was down the intruder would have been unable to exit without Dr McCann hearing him/her (see Sadie's post for why that may not have been the case
http://miscarriageofjustice.co/index.php?topic=5123.msg182192#msg182192); therefore opening the sliding door would not have occurred to account for the change in pressure which may have caused the other bedroom door to slam.
I don’t think it shoots down in flames the theory that a stranger may have hidden in the back bedroom as there would be time still to exit via the other door while Dr McCann was checking the other bedroom for Madeleine and the window.
As Sadie has noted in another post the timing of this ties in almost perfectly with the Smith sighting.
I have always thought Tannerman was very significant and was of the opinion that egress was via the wooden front door; when he was eliminated it was thought that Dr McCann had just missed the perpetrator by minutes, I'm swinging round to the notion he could still have been in the apartment.
No-one would have taken any notice of a father carrying a child along that lane at the back of the block.
B - Pages 967-972 Processo vol 4.
At 11:00am on 4 May 2007 I, IT, assistant-specialist, began to examine the following location:
At apartment 5A, Ocean Club:
- Side of the patio door: One adequate print recovered but not matched to known persons.
- Outside of one patio door: Eight inadequate prints were recovered.- Outside of [the other] patio door: One inadequate print was recovered.- Outside of the external blinds to the children's bedroom: three inadequate prints were recovered.
http://www.mccannpjfiles.co.uk/PJ/FINGERPRINTS.htm#p4p967