Continuity mistake: When Tom Cruise is recruiting customers, he's smoking while sitting outside a hamburger stand talking to two guys. He snuffs out his cigarette in an ashtray (which already had another burning cigarette), but when the shot changes to a long view, his cigarette is back in his hand fully lighted. (01:07:07)
Continuity mistake: In the movie's final moments when Tom Cruise is buying back all his household items, the lady in the cargo bay says "that's everything," except for the crystal egg she throws out into the yard for Tom to catch. You can clearly see many more items left in the truck. But when the truck pulls away seconds later, nothing is left in the cargo bay except our villain sitting on a chair. Where did everything else go?
Visible crew/equipment: While Lana and her friend are staying at Joel's house, after dinner, Lana goes upstairs to visit Joel in his room to see if he wants to go out for ice-cream. As Lana enters the room, the bedroom door swings open and you can see a crew member's hand catch the doorknob, just before the camera pans to the right.
Continuity mistake: While Tom Cruise is dancing in the front hall way and living room in his underwear, the lighting outside changes from daylight to night and sun rays appear on the rug during a part of it.
Revealing mistake: When Joel rides his bicycle to the train station, the film is reversed. The numbers on the train that goes by are backwards.
Factual error: When asked by the Princeton interviewer what he plans to major in, Joel replies "business." Princeton does not offer an undergraduate degree in business.
Continuity mistake: In the scene where Jackie gives Joel Lana's phone number, Jackie writes the number along the length of the envelope. In the scene where Joel uses the number from the envelope, it is seen that the name and number are wrote along the width of the envelope. Also Jackie wrote the number on the back of the envelope and then (when Joel will use the number) the name and number are wrote on the other side of the envelope.
Continuity mistake: In the scene in the hotel lobby, Joel states that he called Jackie who told him Lana would be at the hotel. But Miles ate the piece of paper with Jackie's phone number, so Joel didn't have Jackie's number.
Revealing mistake: When Joel's parents are talking directly into the camera just before they leave on holidays his father takes him into the room with the equalizer. It is easy to see that when the music is playing the equalizer is in fact off. This is proven when the father pushes the button and the red light goes on.
Continuity mistake: When Lana interrupts Joel's interview with Rutherford for the last time, she closes the door and her hair swings into shot. In the next shot, Lana's hair is still tucked under her hat.
Factual error: Tom Cruise smokes a few times in the movie. He has a pack of Marlboro regular which normally have a brown filter, but whenever he pulls a cigarette out of the pack it has a WHITE filter, this leads me to believe it's a Marlboro light coming out of a Marlboro regular package, to protect his film-star lungs.
Revealing mistake: When the Porsche comes to a stop at the end of the boardwalk it is stopped by something that causes it to jerk backwards then roll forward slightly such as a chain or rope. It is moving too fast to stop on its own and couldn't be from a loose board because it rocks freely.
Continuity mistake: Tom Cruise is driving at night. When he pulls up next to some girls, it's day. Then when he starts driving again it's night again.
Answer: Lana liked him, but was not in love with him. The whole Guido house raid was his way of getting what's owed to him, when Joel stole all his business. At the end of the movie, Lana and Joel walked and talked about him going away to college, with no expectations about one another continuing their relationship.