Here is the exact link:
http://www.youtube.com/watch?v=atfDV7imHHY#t=15
Where is the explanation about the sound of the key?
ETA:
Icabodcrane's post at 727:
In the documentary/reconstruction the McCanns commissioned there is a conversation between Gerry McCann and Mathew Oldfield
Gerry McCann explains that the reason they started leaving the patio doors open was because they were afraid the sound of of the key in the lock of the front door would wake the children
Where is Gerry's explanation about the sound of the key?
oh dear
I had a feeling you might try to establish another hair-splitters' convention
The fact I was hoping to establish was that the McCanns, themselves, were best placed to know whether their children were light or heavy sleepers
Cleary, if they thought the sound of using the front door would wake their children then they considered them to be light sleepers
Yet, on that fateful night
neither of the twins roused at all, despite the noisy mayhem all around them
It might be an indication that they
had been sedated
Wouldn't you agree ?