"Yes, he went through Ireland. He didn't sign anything but the officer took his card and said he couldn't have it, that he had to permanently surrender it or apply for a waiver."
You might want to read this about options:
What are a green card holders’ rights if they get stuck at the airport when returning to the U.S.? - Law Offices of Atty Michael Gurfinkel - Immigration Law, Non Immigrant Visas, Family Based Petitions, Immigration Corner, Employment Based Petitions