Continuity: When Stone leaves the building he lives in, there is writing on the wall saying which way to go for each floor. When the killer enters the building, the wall is blank.

Revealing: The opening text describing how London is badly flooded because of heavy rains and global warming is accompanied by an aerial shot of the city. From the level of the Thames it is clear that this wasn't even filmed at high tide, let alone during a flood.

Continuity: When Stone, Durkin and the chief policeman are discussing the killer and Stone's arsenal, the cigar box on the desk closes and moves between shots.

Continuity: After Stone falls asleep, the position of his hand alternates from shot to shot.

Factual error: The forensics report says that Leptospira interrogans is the virus which causes Weil's disease. Leptospira is actually a bacterium.

Continuity: After the first murder in the nightclub when Durkin and the other policeman are on the boat, talking about Stone, their position on the river keeps changing. In some shots they have passed Parliament and Westminster bridge and in others they are still approaching them.

Continuity: When Michelle takes one of the chocolates that are in the shape of a heart, she takes one from near the top. When the killer enters the flat, it is a chocolate from near the bottom that is missing.

Factual error: The radio at the beginning of film says that the flood problem will increase with the approaching full moon. Later it is revealed that the killer only kills when there is a new moon. Since he kills that evening, and tides are highest with full and new moons, the radio should have been warning about that evening's tide, not the high tide in 2 weeks time.

Continuity: When Stone sees the little girl outside his flat, after the murder there, his face is very wet from the rain. He turns around and it is now totally dry.