I find your "saw an opportunity to get rich on the back of a missing child" by writing a book difficult to understand.
Do you also believe the first of its usual extensions, which that Cristovao the same?
What is difficult to understand? He did write a book. And he did get rich.
The reason the book sold is because it was written by the (ex) cop in charge of the investigation, and he had become well known during the case. So his book had more "credibility" than Cristavo's.
The case had attracted lot of interest.
The McCanns were spectacularly made arguidos in the disappearance of their daughter (but only because Amaral could not understand what was evidence and what was not).
Given all that has come out since - even one of the co respondants lawyers said that much of the book had been made up - I find it difficult to understand the posters on here who think Amaral is terribly hard done by and I would love to debate the reasons why.
He took a risk by breaking the rules (how many other ex cps have written about their cases) and he got caught. Tough.