FR will simply say no boarding pass, no boarding.
Nothing to do with them if someones forgets ticket.
According to the Spanish Judge there is a European Law, an International Law and a Spanish Law that state that an airline is obliged to provide
FREE ticket and embarkation documents for their passengers.
So any action by FR going against the passengers lawful rights would increase their liabilities to the passengers and draw further actions and fines from the authorities and consumer protection agencies against the airline.
Andalusia has probably taken a lead from the Barcelona judgement and this will probably be followed by Valencia (Alicante) and Madrid.
It will be up to FR to get some ruling in the European Courts but this seems unlikely.