His mistake was getting the 90 day visa in the first place.
Sloppy reporting here. He came in for 90 days because the Irish are visa waiver for tourism. Visa Waiver differs from the a regular visa, no extensions or adjustment of status allowed. There have been many cases of Brits and Germans etc coming in visa waiver, marrying a USC and then trying to file for green card. No can do, have to leave the country, file and come back in under the proper visa category.