Trotting by being the operative observation, not entering the apartment. Why would it be stupid to assume Gerry had left the apartment to go back to the table? Did stopping and chatting with passers-by next to the apartment figure in his regular routine each evening?
Much has been made of the lack of evidence supporting a burglary ... "nothing was taken".
Madeleine was taken though ... which suggests she was the target.
If entry was made from the pool side ... it would have taken seconds to establish she was not in the first bedroom if they didn't already know exactly where to find her.
If entry was made from the car park side ... it would have taken seconds to find her.
The whole episode could have been concluded in the space of appx two minutes given some preparation.
Ian Horrocks has spent a lifetime dealing with serious crime. It is risible to dismiss his informed opinion on this scenario out of hand because it does not fit the narrative propounded on various internet fora.