At the party meeting starting around 30:00, there are six Soviet officials seated at a long table addressing a group of local party members. The camera cuts back and forth between the officials and the party members, but at a couple of points when the camera cuts back to the officials, they are seated in a different order in different chairs.
The scene at 0:22, KGB meeting: "Train Moscow-Saratov has been stopped by protesters". In reality, it was a train Saratov-Rostov.
At around 28 minutes of this film, there is a reference that Novocherkassk is some kind of Bangladesh. The film is set in 1962 but Bangladesh only became an independent country ten years later.