When General Edel's wife tells him that Kramer is dead, she also tells him that Kramer's body will be transported by the police to Bonn. This makes no sense because Kramer was shot by the police in a brothel located in Bonn.
When Alex calls his sister, the captions read "Red Light District, Bonn". While there are some establishments of that kind in the city, there has never been a red light district.
When Alex calls his sister at the commune the note he has written the phone number on shows the prefix of Bonn (0228). In an earlier episode the commune was shown to be located in Cologne (where the prefix is 0221).
When Alex uses the payphone, the display which normally shows the amount of money inserted stays blank, meaning the telephone is not connected to an energy source. In addition, the lever which is used to insert the money stays in the closed position. On that kind of telephone, the lever always retracted to its original position.
Throughout the show General Edel wears the beret in the wrong way. In this episode it is extremely easy to see in the scene where Edel talks to Lt. Col. Kramer who wears it correctly.
When Lenora Rauch goes to make he phone call postponing her lunch after hearing about Alex's actions she stands in front of a very large date display stating Dienstag (Tuesday) 1 September. 1 September in '83 was a Thursday, only 1981 and 1987 had 1 Septembers that fell on a Tuesday.