Indeed, Benice. I would have done exactly the same thing myself, followed my lawyer's advice. Kate McCann must have been terrified, and in my opinon, had she been guilty of anything she would have broken down and confessed when confronted with the "forensic evidence" (that the PJ didn't actually have....)
I agree with you Rachel. I have slightly mixed feelings over whether it is right for police officers to lie to 'suspects' to elicit a confession, but on balance I think it's acceptable - as it involves no physical violence.
The McCanns would both know that a 100% DNA match would be irrefutable evidence, and if they were guilty of disposing of Madeleine's body then I am sure they would have realised the game was up at that moment. They would know there was no point in trying to get round such evidence. A 100 percent DNA match would have been 'game over' and they would know that to deny it would only be delaying the inevitable.
The fact that they did not break down and confess but continued to insist on their innocence even after that irrefutable 'evidence' was claimed to exist, should have told Amaral that he was barking up the wrong tree.
Unfortunately even if Amaral did realise that - he was simply not prepared to admit it as 'saving his face' was more important to him - and so he was not going to back down. You only have to read his book to know that. IMHO.