You can never get away from the fact....PJ shelved the case as lack of evidence..that doesn't mean no evidence.
The case was shelved as unsolved...you know full well the mcs were not cleared of any involvement how ever you spin your opinions. D
I suggest the Portuguese were precipitate in writing Madeleine off before all the evidence had been rigorously tested and we know from the volume discovered when her case was reviewed by Scotland Yard in 2010.
A prime example of the evidence ignored by the Judicial police was the phone traffic evidence.
I think that after Amaral found nothing incriminating the McCanns and being refused permission to tap their phones he lost interest in taking the information further.
His huge mistake was in not following the evidence he had but in twisting the 'evidence' he did not have. As far as all the phone traffic on the night of Madeleine's disappearance is concerned I think that may be his greatest mistake.
Heri was able to follow it far enough to be able to identify suspects who fitted the profile ... imagine what he could have achieved if he had had all the information to hand as Amaral did.
The difference being that Heri had an open mind and wanted to solve the case ~ as far as Amaral was concerned he (Amaral) was convinced he already had.
Some hours spent by a telecommunications expert back in 2007 using the evidence already in their hands might well have tole a different story. I think Amaral must be a very worried man right now.