I agree. Money doesn't buy happiness or restore a reputation. Had an ordinary citizen written the same book as Amaral no award would have been made. He paid for what he said as because he was an ex policeman, no other reason.
I'm not absolutely sure that even under Portuguese Law an ordinary citizen could have written the same book an got off without getting his/her knuckles rapped for ...
(a) impersonating a police officer
(b) telling downright lies ... and I think you miss entirely that Mr Amaral's book was written
because he was a high ranking police officer and as a result carried weight which a book written by a civilian would not.
Oh and as you have pointed out as an ex- police officer ...
he broke the law.
As well as being unlawful, imo writing a book of that nature showed particular stupidity and arrogance ... his friend Paulo Pereira Cristóvão kept his nose clean on that occasion by billing his book on Madeleine McCann as fiction.