Confusion over Coburn's character's name...

His name is definitely John Mallory. It is clearly printed on the newspaper that Juan's sons look at when they're looting his stuff. There has always been alot of confusion as to who Sean is though. When Juan asks Mallory his name he first says "Sean" but when Juan asks again for clarification Mallory answers "John". Also, in John Mallory's theme song throughout the film "Sean, Sean, Sean" is constantly repeated. It has been suggested that Sean is John's friend from the flashbacks and it seems obvious throughout the film that John feels guilty for having killed his friend. I recommend you watch the special features on the 2 disc special edition DVD. It is suggested in one of the featurettes that John was the traitor and not his friend Sean because of the love triangle revealed at the end, but I cannot do justice to the explanation given. It is interesting if nothing else.

Sean is John in Irish. Coburn's character is John/Sean. Never mind what some gobsh*te of a hack thinks. It is not unusual for an Irish man to be known by his name in Irish and his name in English.

Coburn's character is Irish but has an 'English' name (like Mícheál Seán Ó Coileáin being Michael Collins). When he meets Juan he calls himself 'Sean' to assert his nationality but Juan can't make the name out so he resigns himself to using 'John'.