During the second murder, the killer disappears after the victim sees him illuminated by a flashing light. But on the final "flash", you can see a cut that removes him from the composition just before the light returns in full.
When the first "dead" body is discovered in the wardrobe, there's a closeup of her head and shoulders and you can see her pulse beating in her neck.
When Tao-Li, played by actress Claude Dantes, is being drowned in the bathtub, there is a close up shot of the actress' face underwater to indicate that she is dead. During this scene, Dantes' makes a quick, noticeable movement with her eyes, indicating that she is very much alive. Scene 11 on the DVD.
Guide wire visible when a victim has a spear driven into the wall directly next to her head.
In one English-dubbed print, the handwritten message of the killer is in German.
When the killer slaps Peggy while interrogating her in the English dub, she speaks and screams at the same time.
When Inspector Sylvester calls Clarice into the police station to question the suspects, the shadow of the camera is visible on the wall.
When the killer is dragging Peggy over a toppled cabinet, her stunt double hops on and over it to make it easier for him.