I would have thought you understood such basics
Of course Portugal could ignore the ECHR as they have ignored the rule of law imo
If they want to be known as a country who abused the human rights of the McCanns that's up to them but it would portugal in a very bad light
Not that they would care
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.