Other mistake: When Sarah Michelle Gellar is on the bus with her boyfriend, she sees Kayako face looking at her in the window reflection and panics. When she looks back at the window she sees the normal reflection of her face. Trouble is, her reflection is turning her head and looking side to side, whilst Gellar herself is looking straight and not moving her head at all.Gavin Jackson
Revealing mistake: When the detectives were listening to the message on the answering machine, we heard it say the date was Thursday and states a time the message was left. When the camera shows the answering machine, you can see the display blinking between 1 (the current message) and CL (which indicates the time and date have not yet been set).
Visible crew/equipment: When Susan enters the building's stairwell, in the overhead shot you can see the reflection of the crew or equipment on the banister. It can't be Susan's reflection because she is relatively still, yet the reflection is moving and it is above where she could cast a reflection.
Continuity mistake: When Karen and Doug are walking down the street, right before talking about the Buddhist ritual, they are holding hands (right before turning a corner). In the next shot (right after turning the corner) they are not holding hands at all, and these two shots are supposed to be connected. (00:10:20)
Audio problem: After the detective listens to the message that Susan leaves for her brother on the answering machine, the detective pushes the button to locate the missing phone. The detective as well as another officer begin to follow the sound of the ringing phone which is very loud and audible near them. As they begin walking down the hallway towards the door the ringing becomes muffled and when he opens the door it becomes loud again.Tamala