Many people go out for a quiet smoke when on holiday Sadie so someone standing outside an apartment staring aimlessly into the night sky is nothing unusual. The cigarette butts found outside the apartments are testament to this happening regularly and does not necessarily indicate something sinister.
Your theory is indeed interesting but it is simply that, a theory. I haven't seen any evidence which could in any way lend support to it as being more than just that.
As for Jane Tanner's tears. She sees a man carrying a young girl and 45 minutes later is alerted to Madeleine's disappearance just yards away but chooses not to tell anyone. Her excuse being that she didn't want to alarm Madeleine's parents, a bit weird don't you think?
You are quite right, John, about going out for a quick smoke, however all the flats in this part of block 6 had enormous balconies with much better views to the sea (I believe) and not looking directly at the side of a building (block 5). Close the patio doors and smoke at your leisure ... no need to go elsewhere.
Jane Tanner did not know about Madeleines vanishing immediately because she was looking after E***. As soon as she knew, talking to one of the other women (cant remember who) and hearing the details it clicked into place in her mind and she told the others. She waited for the GNR to arrive and as soon as it was possible she told them.
Very sensitively they decided not to tell The Mccanns immediately, hoping no doubt, that Madeleine had indeed walked, and would soon be found. Also hoping that Janes 'sighting' was of a man carrying his own daughter.
Poor Jane; she was so distressed.