Factual error: When Sally drops Harry off in front of Washington Square Park in Manhattan, the street signs are green with white lettering. However, street signs were yellow with black lettering in Manhattan during the 1970s - yellow street signs weren't replaced with the bright green ones used presently until the mid 1980s. (00:14:10)
Continuity mistake: In the scene where Harry and Sally are having lunch in the diner (the orgasm scene), Harry's napkin is in his lap. You can see it when the camera angle is from the side showing both of them from the knees up. Every time that angle is used, the napkin is in a different place or altogether gone. (00:46:00)
Continuity mistake: Coming out of the diner, on the trip from Chicago to New York, when Sally starts opening the door from the inside she does so with her right hand and the purse in her left hand. The next shot is from the outside and now she is pushing the door open using her left hand with the purse hanging from her left shoulder. (00:10:32)
Continuity mistake: The interior scene on the airplane shows a 707, with the lights mounted on distinctive boxes underneath the overhead bins. The airplane shown landing is a 737, which had the interior lights mounted flush.
Continuity mistake: In the deli scene when Sally is faking her orgasm, the camera movies to Harry. You can see the waiter approaching. When the scene is over, the waiter again approaches to take the order from the other woman (Rob Reiner's mom). (00:46:25)
Factual error: In the classic Katz's' Deli scene Rob Reiner's mother tells the waiter 'I'll have what she's having'. One problem - Katz's is a cafeteria-style delicatessen; there are no waiters that come to the tables in the section where she's sitting.
Continuity mistake: When Harry and Sally are at a restaurant having lunch (this is when she has the fake orgasm), if you look at Sally's sandwich when they show her from behind, you will see that where she has bit into the sandwich has changed. First the bite is on the right, then the middle, then the left, etc.
Continuity mistake: When Harry and Sally leave the diner on their trip from Chicago to New York, a blue Volkswagon pulls into the parking space next to them. During their dialog outside their car, the blue Volkswagon can be seen behind Sally in the first two shots, but is missing in the last shot of her. (00:11:20)
Continuity mistake: When the three women are talking in the open air restaurant, just after Meg broke up with her boyfriend, check the background scenery. It alternates between very cloudy, sunny, and dim and bright, even though the time passed is only seconds. (00:23:25)
Continuity mistake: Also on the trip, there's a conversation scene in the car, in which the camera flips back and forth from Billy to Meg as they chat/argue/flirt. Although the action/dialogue (and therefore the movement of the car) is continuous, the lock button on the driver's side door alternates between "up" and "down" with almost every camera cut. (00:05:10)
Factual error: When Harry and Sally leave the University of Chicago to drive to New York, they pass through downtown Chicago on Lake Shore Drive, which actually would take them 10 miles out of their way.
Continuity mistake: When Harry and Sally are sitting at the table in the diner on their way to New York, Sally's hands change position several times. From the front they will be off the table, in the next shot taken from behind her, they are both on the table. This occurs several times. (00:08:00)
Continuity mistake: When they stop at the little diner (on the trip to New York) Sally opens her menu twice. (00:08:10)
Factual error: Their drive from Chicago to New York takes them through Wilmington, CA. There is a shot of the car going past a Genstar building. This is on the Harbor Freeway in Wilmington. (00:06:35)
Revealing mistake: During the Lake Shore Drive scene, during the late 1970's, check the model years of the passing cars. There's at least one Ford Taurus which did not debut until the 1984 model year.
Continuity mistake: When Harry and Sally are in the car driving to New York, in the front shots you see the car has no rear-view mirror.
Factual error: At one point, on the University of Chicago campus, the main characters drive through Cobb Gate, the ornate Gothic gate at the north end of the university quads. Cobb Gate is now and has been for many, many years, closed to motor traffic. (00:04:15)
Continuity mistake: During the fake orgasm scene, the bite on Harry's sandwich increases and decreases between shots.
Continuity mistake: After their first time having sex, Sally gets up to go get some water. When she comes back, she gets back in bed with Harry and settles herself with her head laying on his left pectoral. There is a quick change of shot, and suddenly her head is much higher, with her head laying on his left shoulder. (01:12:30)
Continuity mistake: During the dinner scene in the restaurant, Marie puts down her glass of cola on the table. In the next shot, she is drinking from the glass again. (00:53:50)
Answer: Sally could be upset for having to drive Amanda's boyfriend, or it could be awkward because they don't know how to say goodbye. There could be a number of reasons why things appear tense between Sally and Amanda, just not explained.
That was a big question mark for me as well when I watched the movie, to the point that I had to re-watch the beginning because I was sure I had missed something; their behaviour doesn't make sense.
Sammo ★