Well seeing as his claim to Irishness is based on his parents, not where he was brought up, he'd presumably disagree with you.
Edit: I don't have any problem with his representing Ireland by the way. It's just by any real world, non-sport definition someone who was born in Britain and grew up here is British (albeit influenced by the culture and country of their parents, of course).
I don't think he's saying that those are the only people that can claim to be British. More that it's hard to claim another nationality if you have such a singular upbringing.
Well seeing as his claim to Irishness is based on his parents, not where he was brought up, he'd presumably disagree with you.
Edit: I don't have any problem with his representing Ireland by the way. It's just by any real world, non-sport definition someone who was born in Britain and grew up here is British (albeit influenced by the culture and country of their parents, of course).