The VFR chart that shows a heliport symbol when there's
three obvious runways is an invitation to error -- once you're past the first airport (that perhaps looks abandoned -- subject to correction by those with local knowledge) the next one must be Londonderry
However as airline crews do not generally carry VFR charts, this has little bearing on this incident.
It would be more relevant to see what different suppliers' approach plates show. If only one "abandoned" airport is mentioned on the plate and the ILS is u/s, you'd spot which
"abandoned" airport and land at the next one
Are both "abandoned" airports shown on the approach plate used?