Continuity mistake: When the two male leads are contacting David on the dock, barrels break off and roll over them, knocking one of them into the water. He emerges all right, only to be struck in the face with a hatchet. He is struck with the blade running from his hairline diagonally across his nose. When his friend finds him, however, the cut is across his cheek.
Revealing mistake: At the end of the film, when the main female character is done taking a shower, she tries to get out of the glass stall. Suddenly, the ghost turns on the shower to scalding hot temperatures. She is unable to get the door to open, so she punches through the glass and climbs out. As this is happening, if you look behind her, you can see that no water is coming out of the shower head, though you can still here the hissing of the water.