After the success of RED (2010), Ernest Borgnine always held out hope he'd be around to reprise his role as Henry the records keeper in this movie. When interviewed in April 2012, he mentioned there was talk about it over the years, and made one request to the producers. "I told them if they do it, I want to carry a gun this time." He kept in touch with Screenwriters Jon Hoeber and Erich Hoeber, and in the end would have had a major role in a sequence at the start of the movie. When Borgnine passed away in July 2012, three months prior to the start of production, his scenes were reconfigured and featured an uncredited Titus Welliver.
Dame Helen Mirren (Victoria) says she's the Queen of England. Mirren played different Queens of England in The Queen (2006), Elizabeth I (2005), The Madness of King George (1994), and the play "The Audience" (2013). She won an Emmy and a Golden Globe for her performance in the 2005 mini-series.
Dunsfold Aerodrome is also the location of BBC's Top Gear (2002) studio and test track. Look carefully, and you can see rubber tire marks, at "Bentley" corner, left by cars during the show's Power Lap segments.
When Frank (Bruce Willis), Marvin (John Malkovich), and Sarah (Mary-Louise Parker) are checking the classified Wikileaks document in the diner, a coffee stain can be seen on the document. This is a Photoshop brush, freely available on the Internet, which can also be found in several other movies.
During the Paris car chase, Sarah (Mary Louise-Parker) says "Happy Trails Bozo!" This is similar to John McClane's (Bruce Willis') words when he shoots Hans Gruber at the end of Die Hard (1988) when he says "Happy Trails Hans".
The initials "S.J." are seen on the pistol grip of the gun Frank (Bruce Willis) gives to Sarah (Mary-Louise Parker). They can't stand for Sarah, because her last name is Ross, and even if she married Frank, his last name is Moses. They likely belong to Prop Master Sylvain Joyal.
After Han Cho Bai (Lee Byung-hun) uses the mini gun to pepper the vehicle behind which Frank (Bruce Willis) and Marvin (John Malkovich) are hiding, Han approaches their hiding place. As he does, an unexplained bullet appears to strike the white van. This is likely a squib that exploded at the wrong time.
Steven Berkoff appeared in this movie as a rich business man involved in criminal activities who hosts his visitors while wearing a dressing gown, exactly like his character in Beverly Hills Cop (1984).
In the scene where Frank (Bruce Willis) and Katja (Catherine Zeta-Jones) go out to dinner in Paris, the scene opens with a shot of the Pantheon dome at night, and then follows Frank and Katja as they walk by a set of steps on the side of a church (Saint-Étienne-du-Mont). The is the same set of steps used in Midnight in Paris (2011). This is where Gil (Owen Wilson) meets the taxi that transports him back in time.
This marks the second time that Mary-Louise Parker's character has been put in danger, either directly or indirectly by Sir Anthony Hopkins' character. The first was in Red Dragon (2002), where Dr. Hannibal Lecter reveals her address to the "Tooth Fairy" serial killer.