(at around 1h 30 mins) In the end scene, when Kroon get's the cable around his neck, he dies with his left hand stuck between his neck, chin and the cable. However, in the last shot he hangs in the opening with both arms hanging down his body.
Lunch at the lift factory: Felix' colleague Spiekerman hesitates a very long time to eat his brown ox sausage sandwich taken from the left side of his lunchbox.
When the boss calls him, this sandwich is turned into white bread and put back on the right sight of his box.
(at around 7 mins) Four men run up the stairs, the last of them is carrying an ax. But in the next scene, the guy with the ax is second in line.
(at around 1h 1 min) What the "professor" explains about the bad robustness of integrated circuits is complete nonsense. However, the "professor" is later questioned as part of the story, so this may well have been intentional.
(at around 34 mins) When Felix arrives at the Office from 'Nieuwe Revu' we see the sound technician moving in the back of the van.
(at around 1h 15 mins) When Felix arrives at Kronenstede at night you clearly see a crew members body reflected in the window when he drives around the corner.
(at around 1h 30 mins) Dummy used for Felix' body when Mieke lifts him from elevator shaft.
A microphone is visible in the bathroom mirror when Felix is standing in front of it.
(at around 20 mins) When the blind man walks to the elevator he tips his stick forward exactly to find the wall, like he is perfectly seeing when to do it.