After the kitten emerges from beneath the car in the garage, its paws are drenched in blood, but while it was under the car, it stayed as far as possible away from the bloody body on the floor there.
Uncle Ralph looks out at Martha and Christine playing hide and seek in the garden, then looks at the book Jenny gave him for 15 seconds, after which Martha, blindfolded, not having moved, seems to realize Christine has disappeared. A later flashback from the same 15 second time period shows Martha, further out in the garden, blindfold off, strangling Christine over 6 seconds and still not having subdued her, making it impossible for Martha to have run off camera, removed the blindfold, killed Christine, retied the blindfold and returned to her original spot during the 15 seconds while Uncle Ralph looked at the book.
When Martha looks at Uncle Ralph's newspaper, there is an article headlined, which translated from Spanish, reads "Another Woman Murdered in Montseny", with photos of the victims. but the article itself, translated, tells of a prize bull returning to the ring at the San Isidro Fair.
In the Poe quote after the credits, "which" is misspelled without the first h, as "wich"
The sign at the local railway station reads "Montseny", in Spain, the setting of the film's action. However, every time the location comes up in the script, it is dubbed "Martigny", which is either France or Switzerland,