The nurse is supposedly alone in the subway station, but during one shot (from inside the subway train as it pulls away) we can see several people walking about on the platform; they all disappear in the next shot.
When the prostitute gets scalped, fresh blood runs down her face. However when Frank pulls off the scalp, the blood appears splotched or dried up.
When Frank is choking the prostitute, her hair noticeably changes between the shots.
The photo that Anna is developing - of Frank accidentally running into a little girl on a bike - is not the same as the distance she was from, when she first took it.
The blue wrapping paper in Anna's present box moves.
When Frank slits the woman's throat on the beach, the knife makes no contact with the throat, even though blood spurts forth from the wound.
When Frank is looking at dead prostitute on the bead, obvious stills are used to not show the woman moving.
Fake fog obvious when Frank appears in front of the car. There was no fog before that shot.
Obvious fake TV screen when Frank is watching it. Video is obviously projected in screen's place.
Obvious fake head used for Frank's decapitation.
Anna cuts Frank with a shovel ripping his clothes in the process. This would be extremely hard to do as shovel is not meant for cutting.
When the prostitute is describing her services to Frank, she says "For 75, I'll take you around the world." But her mouth don't match what she's saying.
When the nurse is hiding in the bathroom and is heavily breathing, the visuals don't match up with the audio.
The nurse cries "Open up!" even though her mouth never moves.
The camera's shadow can be seen several times on some of the mannequins in the final scene.
Vaguely reflected from the inside of the subway windows, when the nurse struggles to get into the subway to escape from Zito.