I immediately thought the fellow must have studied Churchill.
I actually went to Wiki because I didn't think Great Britain was a country, properly speaking, but rather a geographical designation. Turns out it is a "territory of the sovereign state of the United Kingdom of Great Britain and Northern Ireland, and most of the United Kingdom's territory is in Great Britain." Which, I'm sure you already were aware of all that.
So, it's "Great Britain AND Northern Ireland", is it? Does this mean runners from Belfast were excluded from "Team GB"? Brits who understand this, please reply.