In the scene where the Little Bird lands at the crash site, it's not an actor or a stunt man flying the helicopter. It's the actual pilot who landed the Little Bird at the crash site in Mogadishu.

In the scene where Eric Bana is talking with Eversmann after Smith has died, he lets his native Australian accent slip through. The line has something to do with "There will be plenty of time to figure all of that out. Believe me." He uses some sort of faux southern accent through the entire film except for those two words.

According to veterans of the actual event, when the Rangers got the go-ahead for the mission and were getting their gear ready, "Welcome to the Jungle" by Guns N Roses was playing on the base's loudspeakers. There were some half-serious comments among the men about the appropriateness of this song. However, the film's producers failed to secure the rights to use "Welcome to the Jungle," so they substituted Faith No More's "Falling to Pieces"--which is perhaps thematically in line with what happened on the raid.

When the Rangers are going down the ropes, it's not the actors but real Rangers you see.

Orlando Bloom got the role of Blackburn before he became famous through the "Lord of the Rings" trilogy. Being an unknown actor at the time he got the part partly because Blackburn's fate is similar to Bloom's own life. He fell and broke his back when he was younger, just as Blackburn did.