Oliva Sabuco is said to have died at age 26. Although the exact date of her death is unknown, she was approximately 60 years old at the time of her death.
In the movie it is said that Évariste Galois died at 22. In fact, Évariste Galois died when he was only 20 years old.
At the end of the movie, the floor plan of the mechanics is clearly visible. While it would be possible to make such an 'aperture' easier, it is impossible for the elevator - visible in the upper right compartment - to have a hole in the ground. First, the hole in this shot is not visible nor can it be made, as the elevator hole in the ground must move along with the walls.
The black board they are using to solve the problems is still showing the boxes of sweets they drew from a previous problem after they drew on it again to solve the problem related to the switches.
None of the supposedly super-intelligent characters ever thinks of using various small hard objects as wedges at the junctures of moving walls. Also, they waste time moving heavy furniture around instead of breaking out the obviously wooden entrance door before it disappears.