Factual error: Michael Douglas is lying on the couch watching the Jeffersons. Jeanne Tripplehorn arrives and they talk. In the background the theme song to the Jeffersons is playing, but it is the song from the beginning of the show rather than the closing theme.
Factual error: The road where the cops drive on their way back from the beach - where we see San Francisco in the background - is a dead end. It does not lead to Stinson Beach.
Factual error: The light reflections at Tremell's beach house are not the ones an ocean would make. The reflections are from large flat areas of almost calm water - like in basins - but there are none around.
Factual error: When Nick is looking up information about Hazel, the computer says she was released from San Quentin. That's a men's only prison.
Answer: There's no definitive answer to this and the ending is deliberately ambiguous and open to interpretation. The audience is left to speculate whether or not Catherine kills Nick, or if she intended to kill him but changes her mind because she loves him, or intends to kill him at a much later time, and so on.
raywest ★