I assume it was within walking distance, or Brückner had a vehicle for his getaway. The time slot was a call received from 7:32pm-8:02pm, so there was a window of opportunity if Madeleine was abducted shortly thereafter.
PDL is spread over 9.5 square miles. It is home to 3,500 permanent residents. Tens of thousands of holiday makers come and go each season. CB lived on the edge. The fact he made and received calls going through masts in PDL is insignificant given he lived there!
How would CB even know of MM's existence and/or that she was being left, night after night, completely unsupervised in the unlocked holiday apartment?
There is not a shred of anything linking him to MM's abduction and my guess is the German prosecutor is unware of even the most basic details of the case.
CB had lived in PDL for years. Do you not think it a bit of a coincidence that of all the thousands of children that holidayed there during this time he was somehow able to single out, within 5 days of her arrival, a child who was home alone every night, unsupervised, in an unlocked holiday apartment? It is someone who knew these very important details that are key to solving who the abductor(s) were.