"was especially confused that the team representing the United Kingdom of Great Britain and Northern Ireland marched to a banner reading merely Great Britain."

Just one of these anomalys which arise in sport here. For some reason at the Olympics the UK has always competed under the name GB which of course is only part of the UK. Northern Irish people can choose to compete for either GB or Ireland. Cricket is another anomaly. The England cricket team actually represents England and Wales. At rugby union the touring side from the four home nations until relatively recently were called the British Lions. It has now changed to the British and Irish Lions which doesn't quite roll of the tongue so easily though I suppose it is more pc.