Rockin' Reeler, you said "You can still make a good film by keeping to the truth, as Michael Collins will show you".

Maybe you want to correct your statement. In the scene in which Dáil Éireann is meeting in secret, Collins is referred to as the Minister for Intelligence. In fact, he was the Dáil Minister for Finance and the Director of Intelligence for the IRA, the roles had no formal link, and neither position had control over the other.

Harry Boland did not die in the manner suggested by the film. His last words in the film - "Have they got Mick Collins yet?" are however, based on a well-known tradition.
In the film, Collins heads the delegation to London that negotiates the Anglo-Irish Treaty; in reality, it was led by Arthur Griffith, with Collins as his deputy.

The character of Edward "Ned" Broy of the Dublin Metropolitan Police is a composite of many different police officers. The real Broy was a member of G Division, an intelligence branch of the Dublin Metropolitan Police, based not in Dublin Castle - as in the film - but in Marlborough Street. Michael Collins' main agent in Dublin Castle was David Neligan. Like Broy, he also survived the conflict and later headed the Irish Special Branch. In the film the character is killed during bloody sunday.

In the film Collins is told that Frank Thornton was shot in West Cork, a week before his own trip to Cork. Thornton however was wounded in an ambush outside Clonmel County Tipperary, a day before Collins himself was killed.The film is ambiguous in the scene involving Collin's assassination, only showing the assassin asking de Valera if he has a message for Collins.

It then cuts to the assassin returning to meet Collins and telling him where de Valera will meet him the next day. Neal Jordan denies on the DVD documentary that it was his intention to portray De Valera having anything to do with Collins' murder. The film depicts a carload of hardline northern unionist detectives sent to "deal" with Collins and the IRA being blown up in Dublin Castle. In fact, no killings of police took place in Dublin Castle and car-bombs were unknown at the time.

Some commentators have contended that the filmmakers were trying to draw a connection between the Irish War of Independence and the later Troubles, when car-bombs were common. Neil Jordan has also denied this. In the movie, the surrender at the end of the Easter Rising appears to take place outside the General Post Office, whereas it actually took place on Moore Street. Collins says "I would have followed him through hell..." in reference to de Valera; in reality, he was referring to James Connolly, comparing him to Pádraig Pearse.

Connolly was a realist, Pearse the direct opposite. I would have followed him [Connolly] through hell had such action been necessary. But I honestly doubt very much if I would have followed Pearse — not without some thought anyway."

A statement in the film that the Irish Free State was formed at the beginning of 1922, following the Dáil's approval of the Treaty, has since appeared as fact on various websites,[citation needed] even though the Irish Free State did not officially come into being until December 1922.