When Irena does not show up at her apartment when Dr. Judd, Oliver, and Alice are waiting for her, they leave. Dr. Judd hides his cane in the apartment to give him an excuse to borrow Oliver's key and go back in for it. Afterward, he leaves the door unlocked so that he can sneak back in, something that is hidden from Oliver and Alice. Yet, after Oliver and Alice are threatened in the office, they call the apartment to warn Dr. Judd that Irena is definitely dangerous and that he should leave.
When Dr. Judd leaves his cane in the apartment, he tucks it into the sofa cushions. When he returns to the apartment to retrieve it, it is leaning against the sofa.
In the opening scene, Oliver and Alice are standing together at the hot dog vendor's stand in the zoo. After the business of the discarded sketch, Alice has mysteriously disappeared.
When the shepherd arrives and finds the dead sheep, there's a live sheep sitting behind him. After a brief shot of the footprints that he's examining, the film returns to a shot of the shepherd, and the sheep is gone.
The wadded up paper that Irena throws toward the garbage changes shape between when she throws it and when Oliver picks it up and throws it away.
It is revealed at the end that she has a large piece of metal protruding out of her shoulder. However, the whole time she is walking around with her coat covering the wounded shoulder, the coat lays flat on it. Normally the coat would have been lifted by the metal piece, or the metal piece should be piercing through the coat.
When the animal keeper sees the footprints after the sheep are killed, the cat's paw prints become women's shoe prints rather than a woman's (naked) footprints.
Serbia as a country did not exist in 1942. It was simply a county in the kingdom of Yugoslavia.
When Irena and Oliver enter the pet store, the animals start behaving erratically. The store owner then says something to the animals and only her mouth moves, but no audio is heard.
In the end when the taxi runs over the escaped panther, the sound of screeching is heard. However, there is no "thud" indicating that he has hit something. In this case, the thud would be loud, as it is a large animal.
When Irena is alarmed by the woman in the restaurant, she makes the sign of the cross left-to-right, as a Western Catholic would. However, as a Serb, she would more likely have made it right-to-left, as Orthodox and Eastern Catholics do. And if she was Orthodox, she would join three fingers (thumb, index and middle finger) to make the sign of the cross, not use the whole hand.
Irena makes reference to the people of her village having mass, but this is only a Western Catholic term. As a Serb, she would likely be Eastern Orthodox and thus would use the term "Divine Liturgy."
In the Serbian restaurant wedding dinner sequence, in her self-protective crossing of herself in reaction to Elizabeth Russell's "moya sestra" Cat Woman, Irena signs left-to-right, in out-of-character Western Christian style, rather than right-to-left, in Serbian Orthodox style.