Brian Austin Green told Tori Spelling he had been on Knot's Landing and she responded that her dad produced that show. Aaron Spelling did not produce Knot's Landing.
After Shannen Doherty left the writers recommended another brunette and immediately recommended Tiffani Thiessen to replace her. But in reality other actresses (some who aren't brunettes) were offered to take her place such as Drew Barrymore, Alyssa Milano and Alicia Silverstone before Tiffani Thiessen got the role.
In the beginning of the movie, "Jason Priestley" drives into a parking spot in his Mustang. In the background, is a 1992 Acura Integra and a 2005 +/- Chevy wagon at the stop light. The time of the scene is 1989/1990.
In several scenes from 1990 to 1996, including Gulf War 'news coverage' flat screen televisions are being used. While they were around in the early 90's, virtually nobody had them, and certainly not the thin, lightweight ones depicted in this movie.
In a scene that takes place in 1990, Shannen Doherty complains that the costumes make her she "works at the Mall of America" which didn't exist until 1992.
The car Shannen Doherty is shown driving during season 1 is a Mercedes CLK which was not made until the 1997 model year.