When George Raft is told to shoot Peter Lorre by Sydney Greenstreet to prove his loyalty he reaches into a box on the desk and takes out a Colt Detective Special revolver. When the camera changes to the gun in his hand it has changed into a German P08 Luger.
When the man following Ana Remzi stops at a shop; there is a lady customer in front of a mirror being attended to by a saleswoman. But on the following cut; the customer is now not there and the saleswoman is off to the side arranging a flower display.
When Col. Robinson is threatening to give Barton the "third degree", Barton goes to put out his cigarette. He is then shown holding it as before, then putting it out again, between successive shots.
When Barton is in the newspaper office confronting Robinson; the office walls have a dark thin horizontal lining in the middle. But on the following close-ups of Robinson; the walls are plain without the lining. In addition, the room sound has changed. This indicates that Robinson's dialog on the close-ups was done in a different location.
When Mailler begins to hit Barton, his first swing misses is head by a wide margin and Barton reacts a beat too late. (The second blow is more convincing.)
When Col. Robinson is meeting with Bastaki in Istunbul, they are setting across from each other at Bastaki's desk. At one point during their conversation, a house fly appears on the shoulder of Sydney Greenstreet, and it briefly takes flight and lands on his ear, then disappears. :-)
When Mr. Robinson is talking to the newspaper publisher, a fly lands on him and keeps flying around him throughout the shot.
The flies!
In addition to the housefly mentioned on Colonel Robinson's right ear/shoulder while he meets with Bastaki (52:45), there is also a housefly on Nikolai's right cheek when Barton confronts the Zaleshoffs and Rashenko at Rashenko's house, and yet another buzzing Robinson's left ear just after he burns the plans in the ashtray.
In addition to the housefly mentioned on Colonel Robinson's right ear/shoulder while he meets with Bastaki (52:45), there is also a housefly on Nikolai's right cheek when Barton confronts the Zaleshoffs and Rashenko at Rashenko's house, and yet another buzzing Robinson's left ear just after he burns the plans in the ashtray.
When Col. Robinson goes to sit behind his desk early in the film, the camera pushes in quickly towards the desk. As this is happening, moving shadows of the camera rig are visible on the desk and on the wall behind.
When the train is shown leaving Ankara Station for Istanbul (48 minutes in) you see a bit of stock footage showing a (British) Southern Railway class M7 suburban tank engine running somewhere on the South Eastern and Chatham system which runs between London and Kent.
When the train is arriving at the border between Turkey and Syria, there is a shot of a train pulling into a station. A sign on the station is visible and it reads "Estressin" - the name of a train station in Vienne, France, which is 20 miles south of Lyon.
When Mr. Robinson summons his henchmen; Nikolai and Tamara are escorted into the room but the henchmen are not holding any guns nor do they have their hands in their jackets as if they had guns. In addition, Mr. Robinson who is holding a gun has his back turned to them when they enter, Therefore it makes no sense for Nikolai and Tamara to not take this opportunity to put up a fight to save their lives.
When Rashenko offers Barton that he would write down how he killed Ana Remzi; Barton agrees to the offer. But then Rashenko only writes down that he killed her without supplying the details of the murder.