If the German version of the crime is correct Madeleine wouldn't have returned safely home.
If the rape cases had been handled properly by the Portuguese the eventually convicted perpetrator of one crime at least should have been under lock and key.
The crime for which Brueckner was convicted took place in Praia da Luz in 2005 and the evidence was there to be used to secure a conviction and take a dangerous man off the streets, it seems the Portuguese police didn't bother.
Brueckner is the prime suspect in the rape of a young woman the previous year. He is the prime suspect in Madeleine's disappearance.
Justice is still to be done in both of these cases.
If the current poster boy for apologists of what appears to have been a major crime wave in the Algarve during the short time Madeleine was there, had paid for his violent crime of 2005 there might have been no ping from his phone registered on a mast in Luz in 2007.
Therefore with one piece of the current jigsaw displaced would he ever have been brought to the attention of investigators to assume his unique position as chief suspect.
The conundrum is were Brueckner to have been where he belonged in 2007 would Madeleine have enjoyed her holiday and returned safely from it.
I think your post evidences that you are looking from entirely the wrong perspective.