Dame Helen Mirren had to learn how to shoot a gun without blinking so as to look more like an experienced killer. (Blinking was one of the main reasons why the stars in The Matrix trilogy wore sunglasses to mask their involuntary reactions.)
John Malkovich read the first forty pages of the script and liked it, but he asked his agent why he was up for the role of Frank. His agent said that he'd been reading the wrong lines. He was up for the role of Marvin instead.
Karl Urban nicked Bruce Willis with the cup he throws at him in their fight scene, because he threw it faster than Willis expected. You can see the slight look of surprise on Willis' face in the scene.
The purse Victoria used as a weapon was Dame Helen Mirren's own purse. It was given to her as a gift from Giorgio Armani. Since it went so well with the dress she was wearing, and the purse was part of the script, she asked if she could use it. The producers said yes.
In Bulgaria, this movie was distributed under the title "B.S.P." ("Besni Strashni Pensii", which means Furious Frightful Pensioners). But B.S.P. is also a mock title referring to the abbreviation of the Bulgarian Socialist Party (B.S.P.). Its political color is red, and its voters are mainly elder and retired people, just like the R.E.D.s.
Joe's (Morgan Freeman's) fake African dictator character is driven in a Mercedes 600 Pullman limousine, a favorite of world leaders including many developing-world/Communist-regime dictators such as Nicolae Ceausescu, Josip Broz-Tito, Fidel Castro, Pol Pot, Enver Hoxha, Leonid Brezhnev, Kim Il-Sung, Jong-Il Kim, Idi Amin Dada Oumee, and Ferdinand Marcos.
Brian Cox (Ivan Simonov) and Dame Helen Mirren (Victoria) play a Russian and British spy, respectively. In real-life, their ancestry is reversed: Brian Cox is Scottish, and Mirren, though born in England, has Russian ancestry.
In The Bourne Supremacy (2004), Karl Urban played a Russian and Brian Cox played an American. In this movie, this is reversed, with Cox playing a Russian and Urban playing an American. However, neither of these two actors hail from either of these countries, as Cox hails from Scotland, and Urban hails from New Zealand.
Victoria (Dame Helen Mirren) gets into Vice President Robert Stanton's (Julian McMahon's) event with an invitation apparently bearing a pseudonym. An early draft of the script indicates that the line originally had the name as "Ms. Smith", but in the scene as shot, the woman at the entrance addresses her as "Ms. Brown". After the death of her husband, Britain's Queen Victoria was said to have become romantically involved with one of her servants, and slanderous rumors circulated that she had even secretly married him. His name was John Brown; thus, those spreading the rumor derided Victoria as "Mrs. Brown".
Bruce Willis (Frank Moses) and Julian McMahon (Vice President Robert Stanton) have been engaged to model and actress Brooke Burns. McMahon and Burns were later married from 1999-2001, while Willis and Burns were engaged for part of 2003-2004, but were never married.
The first theatrical movie based on a DC Comics property not made by Warner Brothers. (Batman: The Movie (1966) (from Twentieth Century Fox) was a spin-off from a television series, and Superman (1948) (from Columbia Pictures) was a serial.)
"Love's Savage Secret", the title of the "terrible", "awful" romance novel that Sarah (Mary-Louise Parker) is reading (and loving) could be a composite of two romantic fiction novels written by Joan Wilder (Kathleen Turner) in Romancing the Stone (1984): "Love's Wicked Kiss" and "The Savage Secret".
During the kitchen shoot-out with the Secret Service, Marvin (John Malkovich) says to Victoria (Dame Helen Mirren), "I remember the Secret Service being a lot tougher." It's possible that this is a nod to his character in In the Line of Fire (1993).
The C.I.A. operative posing as a Police Officer is named Endercott. Former C.I.A. Agent Robert Baer, who served as a consultant for this movie, was initially given the cover name Endacott when he became a C.I.A. Agent (from his book, "See No Evil").
Ivan Simonov (Brian Cox) is the Russian S.V.R. "rezident", the Russian equivalent of the C.I.A. station chief. It is extremely unlikely that he would be unknown to the Secret Service and current C.I.A. Agents, especially considering that he was known to Frank Moses (C.I.A.) (Bruce Willis) and to Victoria (MI6) (Dame Helen Mirren), who was ordered to kill him. He would not have been allowed anywhere near Vice President Robert Stanton's (Julian McMahon's) fundraiser. However, this is a fictional story based on a comic book, so anything is possible.
The musical number that the band plays when Ivan (Brian Cox) and Victoria (Dame Helen Mirren) dance, at Vice President Robert Stanton's (Julian McMahon's) fundraising event, is the same number played by the country club band in Caddyshack (1980) prior to Al Czervik (Rodney Dangerfield) tossing the band members some money.
When Frank Moses (Bruce Willis) first meets Sarah (Mary-Louise Parker) in her house, he tells her she's in danger because they know he likes her because they know he's been talking to her. Yet later, when Agent William Cooper (Karl Urban) is talking to headquarters he says, "He made twenty-three calls to Pension Services and that didn't stand out to you?"
When Frank, Sarah, Joe, and Marvin show up at the Eagle's nest for assistance from Victoria (Helen Mirren), Dame Helen is posed behind a flower arrangement, reminiscent of the way she posed behind flowers in the 2003 film "Calendar Girls." This time, however, she isn't nude.
On the accompanying official score album, all twenty cues on the tracklist by composer Christophe Beck are impressively titled to fit the acronym RED just like the title of the film (e.g. "Rotating Enforcement Device," "Regular Easygoing Dudes," "Rehash Every Detail," etc.).
When William Cooper (Karl Urban) is leaving Henry's (Ernest Borgnine's) vault he starts to use a cell phone. Personal cell phones are never permitted inside C.I.A. facilities, and their use is discouraged in outdoor areas like parking lots. Very few people have government issued cell phones. However, since this is a fictional story based on a comic book, anything is possible.
After the scene in Marvin's bunker, he, Frank and Sarah are sitting at a dockside table. Sarah says something about catching Gabriel Singer in Mobile, Alabama. She pronounces it "Mobul" but as every Southerner knows, it's pronounced "Mo-beel." Mary Louise Parker was born in South Carolina and lived in Tennessee and Texas growing up so you'd think she'd know the correct pronunciation, her character evidently is not from the South and may even be from Ohio, thus she wouldn't have heard the correct pronunciation.