The Oktoberfest scene at the beginning of the film was not staged. The filmmakers hid cameras to prevent people from knowing they were being filmed.

Walter Matthau, who lost family and friends in the Holocaust, only agreed to travel to Germany to shoot the opening Oktoberfest scene on condition that his son, David Matthau, was cast as Ross.

After agreeing to be filmed in Germany, Walter Matthau resisted filming scenes showing him drinking at Oktoberfest until his stepdaughter Lucy Saroyan was given the role of Carla, the pilot who flies him in her seaplane. After arriving at their destination and being paid, she tells Matthau's character that he reminds her of her father. His response is, "That's always been my problem."

Sam Waterston arrived late to begin filming because his role in Heaven's Gate (1980) ran much longer than anticipated. By the time he began his work as Cutter he was exhausted. As a result people mention how awful he looks two times, and he blames jet lag.

The photograph of Ned Beatty on the desk where Matthau is typing his book is first seen with a smiling face. As the writing continues throughout the film, the expression gradually changes to anger and is finally shot off the desk, the bullet hitting the middle of his forehead.

The names of the characters "Ludlum" and "Westlake" are taken from authors Robert Ludlum and Donald E. Westlake.

The name of the character "Follett" is taken from author Ken Follett, a popular writer of spy novels and political thrillers.

The U.S. State Department issued several "real" passports for Matthau's character's several aliases. The documents were filmed in tight close-ups and were kept in a safe at the production company's office for security. When filming was complete, they were returned by hand to the State Department.

Glenda Jackson was reportedly delighted at the prospect of re-teaming with Walter Matthau after having co-starred with him a couple of years prior in the romantic comedy House Calls (1978).

Continuity

Mrs. Myerson's voice in the two phone calls sounds different from that of actress Anne Haney who plays the part in a later scene.

The movie is plausible up to the point where Kendig was able to transition from the biplane across an open field, under the watchful eye of four people in a helicopter without being seen, to hide in the shack with his radio control box and fly the airplane. This is very incredulous.

In the scene where Kendig is chased by FBI cars in Georgia and spills oil on the road, it is shown as he left it and again a moment later as the FBI cars careen off the road. The splash pattern of the oil on the road is different in the two views.

When the agents from the CIA and FBI near Myerson's house, his car is in front of the house, but when they start shooting, the car is no longer there.



Incorrectly regarded as goofs

In the scene at Myerson's house in Savannah, Kendig is getting ready to start typing and glances at a photo of Myerson. When the photo is first shown, Myerson is facing to his right, but when Kendig picks it up, Myerson is facing to his left. The photograph changes several times after this. In fact, each change is intentional and is intended to show Myerson getting more frustrated and downtrodden as the plot progresses, culminating in the picture being shot in the forehead by one of the FBI agents (as explained in the introductory video on the DVD).



Errors in geography

When Glenda Jackson leaves her house in Salzburg in her car "to get some ice" it shows her driving instead to a ferry boat which takes her to England, apparently arriving later the same day. The distance from Salzburg to the English Channel cannot be driven in one day.

Myerson's house is supposed to be in a suburb of Savannah, GA, but the address is stated as being in Adairsville. Adairsville is north of Atlanta, more than 300 miles north of Savannah.



Character error

Miles mails his first chapter to the CIA in Washington, D.C., but the CIA headquarters building is in Langley, Virginia.

When Kendig puts on his reading glasses in Myerson's office to examine the photos on the wall close up, he looks over the glasses rather than through the lenses to view the pictures. There's no point in putting on glasses if you're just going to look over them.

Agent Ross's passport shows a birth date of 30 January 1930, but actor David Matthau was obviously much younger (born 1953).