Continuity mistake: During the dance, there's one song where the guys stand in one line and the girls in another, and the couples take turns walking down the middle. In one shot, Danny is placing Sandy in line, and a couple (the woman has a blue dress on) is already starting down the middle. Then it cuts to another angle and no one is in the middle. Back to the first angle, and people are in the middle again.
Continuity mistake: In the Greased Lightning dance scene, look just in front of the last white desk on the right side during the dream car segment. One of the dancers knocks a tyre off a stand and it falls in front of the desk. A shot or two later, the tyre is back up on the stand. (00:40:05)
Continuity mistake: When Principal McGee does her announcement to all the students at the beginning of the film, you can see a flag of the United States at the far end of her desk, but when we see a close-up of the Principal, the flag is now right in front of her.
Continuity mistake: In the scene where the whole gang meets at the diner, the waitress brings out Danny and Sandy's food, and you can see the drinks they have ordered are a dark pink colour. In the next shot that they appear, the drinks are a lot lighter shade, almost pale pink.
Continuity mistake: When Marty and Rizzo walk past the TV truck, Marty says "Rizz!" and they stop and look at Kenickie, whose head is tilted to the right, but in the next scene his head has moved to the left.
Continuity mistake: When the three T-Birds go to moon at the TV camera during the performance of "Blue Moon" at the National Dance Off, you can see there are two red balloons in front of Doody, but in the next shot the balloons have disappeared.
Continuity mistake: Just before Kenickie runs up behind Patty Simcox and lifts up her dress she standing at the back of the hall clapping her hands, she is not in the dance contest.
Continuity mistake: When Sandy is asking Rizzo if she's going to Thunder Road, her hair is curled under. When she's watching the race and then talking to Frenchy after Danny wins, her hair is flipped outwards.
Continuity mistake: After the Song "You're the one that I want" when Danny is doing the test your strength game you can see Frenchy running from the Ferris Wheel a second time when Rizzo and Kenickie start kissing again, when that scene happens just before the song. (01:44:50)
Continuity mistake: In the pre-credits sequence, when Danny and Sandy on walking on the beach, Danny is on the left and Sandy is on the right. However, in the next scene, when they kiss, they have suddenly changed positions. (00:00:40)
Continuity mistake: During the basketball lesson with the team and Danny, Coach Calhoun is holding the ball and tells him, "You have to dribble." At this point you can see that Danny is very close to the coach, but in the next shot he is further away from him.
Continuity mistake: During the dance contest, when Kenickie and Cha-Cha are dancing around like crazy (when she puts her foot up on his shoulder), you can see Danny and Sandy in the background, standing on the sidelines. Given that they're the last couple on the floor at the end, they should still be out dancing at this point.
Continuity mistake: When Sonny enters the sports hall for the National Dance Off, he twangs Chisum's braces and walks towards the bandstand. Chisum is well away from the doorway at this point. However, in the next scene, Chisum is now standing near the doorway and Sonny is walking away from the bandstand.
Continuity mistake: Widescreen version: When Vince Fontaine introduces Johnny Casino & The Gamblers at the National Bandstand, Blanche is seen walking off the stage. In the next scene, she is on the stage, dancing with the band.
Continuity mistake: Once during the dancing scene you can see Vince Fontaine standing on Marty's left side, and then suddenly on her right. (01:10:16)
Continuity mistake: At the dance when they do that partner dance down the middle of the gym, as the lines form Kenickie and Cha-Cha start dancing down it, then the next shot its another couple first down it, and then a couple of shots later Kenickie and Cha-Cha start going down the lines again.
Continuity mistake: When Danny is running on the athletics track, he falls over one of the hurdles. He then picks him up and Sandy goes over to see if he is okay. You can see that Danny is walking towards to the field section of the track, but in the next shot he is walking away from Sandy.
Continuity mistake: When Jan is eating her lunch, she is joined by Marty and Rizzo. Jan then says "Did you guys get a look at Zuko this morning?" and you can see she has nothing in her right hand, but in the next shot she is holding a fork.
Continuity mistake: During the race at Thunder Road, look at the length of the wheel cutters - they keep changing length throughout the whole race. Plus we only see one come off, but before the crash the two Westside ones are missing.
Continuity mistake: When Danny and Sandy enter the sports hall for the National Dance Off, there are four people behind them sitting on the spectator benches, but when Doody and Frenchy enter the hall in the next shot, the people have disappeared and there is now a woman in a pink dress behind the benches.
Answer: It is implied that Danny and Rizzo had a previous romantic relationship of some kind. When Jan says, "Did you guys get a look at Zuk this Morning? Looking pretty good this year, huh, Rizz?" Rizzo replies, "that's ancient history." Later, when Danny says, "you're looking good, Rizz, " her answer, "eat your heart out," also suggests some possible residual feelings on her part. I think that's why Rizzo enjoys tormenting Sandy and Danny by reintroducing them at Rydell at a moment that she knows Danny is going to save face around his friends.
Michael Albert