The stones which Kristian brought from Rio de Janeiro in a suitcase are named Uranstone or Uran in the movie. However the actual name for this kind of mineral is Uraninite. Also they contain radioactivity, so they should only be out in dust- and radiation-free units and never be in living rooms or similar. Also Anita and Kristian are touching the stones with their bare hands, but they should only be touched with gloves and mouthpiece.
Before leaving the apartment Gerti is picking up the red bag with one hand, which doesn't seem to be heavy. Then she puts it back to check the food elevator. But when she picks it up again she suddenly complains, how heavy the bag is. It is obvious that the bag was not heavy and she acted like it is..
At the end of the movie Dr. Kellermann said that he has to me in the ministry the next day and stops at the hotel later. However the same day he is also at the opening of the Olympic games of Waldsee in the school where he is going to be a principal, already dressed in a suit, while his daughter Anita is with Kristian searching for the lost stones. How can all this happen in one day when he supposed to be in the ministry?
Earlier Dr. Kellermann named Gustav Kellermann, according to the letter read by Pitzelberger to Hanni and his colleague. However later when Kristian gave a fake name to Hanni at the reception, calling himself Dr. Michael Kellermann, she is frightened and mistakes him for the actual Kellermann, even through they had a letter with the actual name. However this could be deliberate as it was said in the movie that Dr. Kellermann wants to study unremarkable and they don't want Kellermann to come here.