Continuity: When Professor Catro is shot, blood splatters onto Chema's face and drips down; in the following shot, there is no blood visible.
Continuity: When professor Figueroa finds the door to the secret library of snuff movies, before he enters, he wears glasses. In he next shot, as he enters the door, the glasses are gone, but they come back some shots after.
Boom mic visible: When Angela runs out of Castro's office, a boom mic is reflected in the door, just before he yells to her.
Revealing mistakes: In the cave, when Castro gets shot, the gunshot would have deafened or at least severely affected the hearing of Chema and Angela.
Continuity: In the final garage scene, the height of the camera has changed from approximately waist level to head height.