I do;
The Supreme Court of The Republic of Portugal is the highest court in that state, there being no mechanisms for overturning it's rulings.
It cannot be overruled by the ECJ as that it is outside the scope of the ECJ which rules on European Union matters not matters of national law.
It cannot be overruled by the ECHR as that is outside the remit of the ECHR.
If a plaintiff makes a complaint against a member state of The Council of Europe it may, if admissible, eventually be heard by the ECHR who may fine the member state and ask them to change their laws if deemed desirable by the ECHR. The fine may be paid to plaintiff as compensation. Just as guide to quantum Steel and Morris were only awarded £50k by the ECHR against the UK in the McLibel Trial.
Then of course the state may just ignore the ruling as over 75% of states do.
So as it sits at present:
The ruling of the SC remains and will so in perpetuity.
The Drs McCann will have to pay the costs awarded by the courts plus their own legal costs unless someother arrangement satisfactory to all parties be agreed.
Appealing to the ECHR is a long winded process whereby one may, apparently, finish up with an unenforceable piece of paper.
You have missed out what is perhaps the most important point
The ECHR can rule that the member state applied the law incorrectly
This useless piece of paper would show that the McCanns had been the victims of a miscarriage of justice by Portugal and that amaral had indeed defamed them. It could show just how much the SC got the law wrong