If the McCanns were not able to EMPIRICALLY PROVE the extent of damage caused, then the case against Amaral may fail.
A sad day for Portugal, however, if it's considered fair to accuse people of criminal acts, subsequently echoed and amplified by others, particularly when the people concerned have never even been arrested, let alone charged.
In the Portuguese trials against various PJ officers, they were considered innocent until the results of the final appeals (and some even appear to have maintained their jobs in the PJ).
Whatever the outcome.... it will not mean that everything that Amaral has ever spouted was the "truth", which is no doubt how some will interpret it, conveniently substituting the putative likely results of UK libel laws (requiring proof of allegations) for PT proof of damage ones.
If the case against Amaral is dismissed, I wouldn't put any bets that accusing people based on "interpretation" of "misunderstandings" of evidence is likely to stop the floodgate of pent-up vitriol, waiting for a verdict to be announced so as to be expressed in mainstream media as "fact".
Apples and oranges. And more than a few bananas. Plus a few squirts of sour citrus fruits.