Continuity: Halfway through the first scene in Diana Christianson's office, the door, which had previously been open, is closed. Later, she walks over to the door and closes it again.
Revealing mistakes: Every one of Howard Beale's shows has the same studio audience (note the man in the black vest, with long hair and a beard).
Continuity: When Max Schumacher is telling Howard Beale a story on the sidewalk in front of their building, he backs up into the street a few times as cars pass by. At the very end of the story, as he hugs Beale, an empty cab is parked on the sidewalk, right behind where he was standing in the street.
Audio/visual unsynchronized: After Howard's first on-air meltdown, as Max and the other network executives sample the reaction from other networks, they watch the other newscasts from a bank of three sets, each tuned to a different channel. As Max says he is not surprised each of the other networks is leading with the Beale story, he lowers the volume of each set in turn. The volume drops before Max's hand reaches the dials.
Anachronisms: The obituary for UBS Chairman of the Board Edward George Ruddy is shown with the character's information superimposed over the title area, with real January, 1975 obituaries for Revlon founder Charles Revson and screenwriter Sidney Buchman listed below. Additionally, the movie is set during fall 1975, months after Ruddy's death.
Errors made by characters (possibly deliberate errors by the filmmakers): Early in the film, after Howard Beale says that he's going to kill himself on-air, he's on the phone with Schumacher (Holden) angling to get his job back, and he mentions that he "has 11 years with this network." Later, following his on-air rant that "he ran out of BS," he's confronted by the press in the lobby of UBS where he says, "Every day, five days a week for 15 years, I've been sitting behind that desk..."