You must love whooshing any adverse opinions! I find what you did totally despicable and shows that you do not believe in freedom of opinion, especially when it concerns your dear beloved devious duo of parents. What you did is nothing to be proud of.
If you did not agree with what was written, all you had to do was point out the "errors" out in the review section, which would have been much more effective than just making the book disappear. BTW, I read it and did not find anything libelous in Pat Brown's kindle book. I would be interested if you would please let us know what exactly in the book could have been considered libelous.
If the McCanns felt that the book was truly damaging, all they had to do was hire a lawyer in the US and sue Pat Brown. However, since freedom of opinion is highly regarded there, they probably wouldn't have gotten anywhere. So that's why they sent their henchmen, Carter Ruck, to threaten Amazon.
US law is complicated because there is federal law (applicable in all states) and there is individual legislature of each state (state law). But as I've always understood it, broadly on libel, there is a set of rules that applies to private citizens (where the bar of what amounts to libel is relatively low) and there is libel of people in public or professional positions (where the bar is much higher and libel is much more difficult to prove).
Portugal has a guarantee in its constitution that protects the right of citizens and (by extension) visitors to a good name.
From a position of first co-ordinator of the shelved enquiry Amaral has trampled rough-shod over the McCanns' right to a good name.
That's why he is in the fix he's in.
And a group of (mainly) foreigners to Portugal are trying to bale him out.