Episode Nine - S2-E2
Continuity mistake: The necklace James took from the coconut in Dr. Jacobi's office in the previous episode had a gold chain. When he gives it to Agent Cooper in this episode, it's on leather.
Continuity mistake: At One Eyed Jack's, when Agent Cooper and Jacques are sitting and talking there are 2 glasses of beer on the table. In one shot Jacques finishes a glass. When he gets up, both glasses are full. (00:10:20 - 00:11:40)
Continuity mistake: In the hotel lobby, the chair that Leland knocks over switches between shots between lying on its side and on its back.
Continuity mistake: The plate, bread and milk that Pete drops on the floor change position between shots.
Continuity mistake: At about 23:21, Dale Cooper is writing on a chalkboard that has the letters R and T on it, not circled. Moments later, at 23:30, the letters are circled, even though Cooper has not marked the board. (00:23:20)
Suggested correction: Actually, there is a cutaway shot to the two policemen, and when the shot changes back to Cooper (with the letters now circled, as you say), he does have the chalk in his hand and then circles the "J." I think it's implied he circled the R and T in the cutaway. There was enough time.
Continuity mistake: Nadine decides to lift leg weights beside Mike. She sets it to 600 pounds. However, whenever it changes view to her lifting from the angle of Mike, whenever the coach asks her to join the team, you can see that Nadine is not lifting any weights. (00:19:45)
Episode Five - S1-E5
Continuity mistake: When Leland Palmer suffers another mental breakdown during the party, Benjamin Horne tells Catherine Martell to dance with him, emphasising this by pointing his finger. The shot then cuts to Leland Palmer, and in the background, you can see Horne telling Martell again to dance with him. (00:39:57)
Continuity mistake: During the barroom brawl, Bobby and Mike start fighting and Donna escapes out the back exit with one of the bikers. They leave on his motorcycle to meet James. Dale and Sheriff Harry are trailing them. Then a cut back to the barroom and Bobby and Mike are still fighting the bikers. However, if you look in the top right of the shot, you can see Donna and the biker still behind the bar, trying to leave. (01:19:13 - 01:19:50)
Continuity mistake: When Lucy is badly explaining to Sheriff Harry Truman which phone she transferred the call to, in the window reflection, you can see the Sheriff moving around the office to find the phone. But in the close-up cutaways of Harry, he is standing in one place. (00:05:07)
Continuity mistake: When Pete Martell finds Laura Palmer's body, there is a piece of wood on the ground near Laura's head as he approaches her. It disappears between shots. (00:04:20)
Continuity mistake: The credit has "Lucy Morgan." Later, her name becomes "Moran"; see the nameplate on the desk.
Continuity mistake: After Leland is pulled over by the police, he goes to open the boot of his car, and he is wearing dark gloves. When he rummages in his golf bag containing the body for a golf club, he is wearing no gloves. Then he holds the club in the air to show Cooper and the gloves are back again.
Continuity mistake: When Donna confronts her mother about Ben Horne, she is asked to pass the peas. Her mother fills her plate with peas. Only a few sentences later Donna is asked again to pass the peas and her mother fills her plate again, without having eaten anything in between. (00:42:10 - 00:43:10)
Continuity mistake: When James and the blond women decide to have a cup of Champagne together, James put the bottle down on the seat and while they're discussing the bottle vanishes. (00:33:30 - 00:34:15)
Continuity mistake: At the Roadhouse, Donna has her hand on the only glass of drink on the table, but whenever the shot cuts to James, the drink is next to him with nobody holding it.
Continuity mistake: After Nadine smashes the milkshake glass, the cream and blood which has splashed on her face changes between shots.
Continuity mistake: The amount and pattern of the golf balls on the Palmers' living room floor changes between shots.
Continuity mistake: Ben Horne's glasses are knocked off during his arrest at the Great Northern. No one picks them up, but when he is brought around the corner of his desk, he's wearing them again. (00:28:50 - 00:30:30)
Continuity mistake: The position of Blackie's fingers on Audrey's chin switches depending on the angle. From behind, her fingers are straight; from the front, her fingers are scrunched up/bent.
Continuity mistake: When the three drinks are placed on the bar in front of Cooper, the sheriff, and the judge, the amount of foam on top of each drink changes drastically between angles.