Continuity mistake: When John Cusack is trying to persuade Eugene Levy to give him Sara's details, the camera angle is cutting from one to the other. In one sequence, when we see John Cusack, Eugene Levy is clearly smiling (reverse angle), but from the front shot he's looking very serious.
Continuity mistake: Towards the end of the movie, Sara (Kate Beckinsale) runs to the Waldorf-Astoria to stop Jonathon's (John Cusack) wedding. The first time she turns to leave the room where the wedding was to be held, she has just a few drops of sweat showing through her blouse. The second time she turns to leave the room, her back is drenched in sweat.
Continuity mistake: At the end of the movie where Jonathan is laying down on the skating rink with all the people skating around him, it starts to snow, and you can see several small puddles all over the rink. The shot flashes to show him still lying in the exact same spot with no skaters anywhere (to signify a time lapse), but all of the puddles look exactly the same, haven't changed a bit. If people were still skating they probably would have enlarged, and if they'd stopped they should have refrozen.
Continuity mistake: Originally, the director was going to have the first meeting between Jon and Sara take place 10 years before they finally meet again, but later changed the difference to 7 years. When there is the close-up of Sara's Bloomingdale's receipt, the date printed is 1990, but for a 7 year difference, it should be 1993.
Continuity mistake: When Eve is getting into the taxi cab and says farewell to Sara, as the taxi pulls away, you can see in the background three people exiting the revolving doors of the Waldorf Hotel. The very next shot is a medium closeup of Sara watching the cab drive off, and in the background those very same three people once again exit the revolving doors of the Waldorf Hotel.
Continuity mistake: This mistake appears when a truck rolls by Sara and Jonathan just as Sara is handing her phone number to him. The camera is close on Sara and Jonathan, but when the shot goes wide, you can see Jonathan's feet turn completely around AS the truck is rolling by, and then the next jump cut shows him turning around AFTER the truck rolls by.