During filming at Stowe School in Buckinghamshire, where Russell Crowe's character watches his son play rugby union, one of the students asked Russell Crowe for some acting advice. After their conversation, Crowe remembered his serious interest in acting and sent him autographed posters and photos from his film, Gladiator, and wrote a letter saying, "A thousand mile journey begins with one step." The extra, Henry Cavill, went on to pursue his acting career and ultimately landed the role of Superman in Man of Steel (2013) with Russell Crowe playing his father.
Will Gaffney, stand-in for David Morse, was killed in a freak accident when a truck on which he was riding suddenly turned and drove off a cliff while being filmed in Quito, Ecuador. The movie is dedicated to him.
Originally it was planned that all extras were to receive the normal pay used for American extras. But the Ecuadorian government, who could not afford to have their actors paid that well demanded that the movie pay Ecuadorian salaries.
Kessler's bible is used for two maps of the area. The main map is drawn over Luke 21-22, which talks about the return of the Son of Man (Thorne will come and save Peter Bowman). The second map has a passage marked out, Matthew 5, which discusses the wrongness of revenge and loving your neighbor.
During the scene at 1:40 into the movie when he says, "these guys are my Panama crew", you can see a piece of cardboard on the wall behind with "JUST CAUSE" written on it. Operation Just Cause was a U.S. invasion of Panama to capture Manuel Noriega, military leader and drug criminal - a storyline very similar to the movie's plot.
Russell Crowe mentions being in the Special Air Service Regiment in Australia, then leaving to join the British SAS because of a lack of action. Post Vietnam in Australia operational deployments were highly limited, and often soldiers went entire careers without deploying on operations. The British armed forces had more involvement internationally. This has since changed for Australia since the late 1990's