Sounds to me like such a technical difference that is no difference at all....he could have gone to one of the, too, many so called universities in England unless he is studying Welsh?!!
What he's done is gone to another part of the same country to continue his education. The higher education system in the United Kingdom is universal. It's common for students end up in different parts of the United Kingdom; I'm English and went through exactly the same system as Scots when I went to Edinburgh.
Steffon Armitage has left both England and the United Kingdom to enter a separate labour market in order to earn more money and enjoy a different lifestyle/culture.
One is caused by an odd difference in legal and sporting boundaries, the other is caused by what appears to be stubborn avarice.