The Attorney General, JohnLarkin, told the Stormont finance committee on 19 September 2012 that the retrospective nature of the bill might fall foul of the Convention.
The O'Hagan family's lawyer, Niall Murphy, said they would be considering options including making representations to Northern Ireland attorney general JohnLarkin QC over an inquest and potential civil litigation.
Appearing before a three judge Court of Appeal panel on behalf of the department and minister Edwin Poots, Attorney General JohnLarkin QC contended there was nothing in the documents that assists the FPA's case.