Judith Weidner wrote the original screenplay which then was rewritten by Jaschar Marktanner. The credits however say "Judith Weidner & Jaschar L Marktanner" - normally, an ampersand instead of the actual word is only used when two or more writers wrote the script together.
When Dr. Vogt signs the petition in the Close-up, the name Nastasja or Natasha Kinski can be seen as one of the signatories. This was not intended by the director and rather a joke snuck in by one of the crew members.
When Dr. Vogt writes his address in the petition in the Close-up, he neither includes a postal code nor a town.
One of the signatories in the petition hasn't actually signed but only included the name and address.
When Jessica enters the room and sees Dr. Vogts standing in front of the machine, the latter makes no sound although its gear wheels clearly grind and the lid goes up and down.