Continuity mistake: In this episode we get to see when Barney lost his virginity to Rhonda, The Man Maker. They had sex in her bed. But in season 2 (12th episode, First Time In New York), Barney says that his comforter smelled like menthol for a week.
Say Cheese - S5-E18
Continuity mistake: Barney claims in this episode he never "takes a bad picture". But in earlier episode "The Sexless Innkeeper" there were plenty of bad pictures of Barney in Marshall's Best Night Ever Montage.
Slapsgiving - S3-E9
Continuity mistake: Marshall turns on the computer, and a readout pops up clearly displaying 2h 45m left on the countdown. He then says "look at that - that means we're in the final hour left of the countdown".
The Playbook - S5-E8
Continuity mistake: In season 5 episode 8, Marshall and Ted are playing on an Xbox 360 Console. If you look carefully, you see that Ted's Xbox controller has no batteries in it, yet he is playing the game with Marshall, and then a few scenes change and so do the batteries. Scene 1, 12 minutes and 23 seconds: Marshall's remotes has a battery in while Ted's is out. Scene 2, 12m 40s: Marshall's Xbox control has no battery in. Scene 3, 12m 51s: Marshall's battery is back in the controller. Scene 4, 12m 58s: Marshall's battery is out again. Scene 5, 13m 44s: Marshall's battery is back in.
Continuity mistake: When Randy reveals that he didn't sleep with Robin, the blood from his nose switches nostrils between shots.
Continuity mistake: In the closing scene at the bar, the level of beer in Marshall's glass goes up and down without him drinking any. Also, the glass goes from in his hand to on the table in an instant between shots. (00:19:25)
Continuity mistake: When Lily is selling her favourite dress and is saying how she got a two syllable damn, the flashback shows her with the hairstyle she got after Coming Back from San Francisco, even though she said it happened in 2004. She should have had her shorter, lighter coloured hair. (00:15:10)
Continuity mistake: When Robin leaves to get Battleship, Barney thinks they're going to have sex, whips his belt off, and throws it on the floor. When Robin returns, he's neatly folding his pants and draping them over a chair, and his belt is still threaded through the loops. (00:16:20)
Suggested correction: He could have easily done that himself so it was easier to put back on afterwards.
This correction is too much of a stretch. It would make no sense for him to take off the belt and throw it to the ground in the first place. He was alone at that point, so he wasn't doing it to impress anyone and he's been in this position before.
Continuity mistake: When Barney is in the Professor's office, we see the professor put a red pen down on her desk and her hands are then empty. In the next shot, she suddenly has a blue pen in her hand.
Continuity mistake: When Lily and Marshall are talking in the kitchen, we see Lily put down the recipe card to the left of the jar of mayonnaise. The shot changes and the card is now to the right of the jar. (00:06:25)
The Pineapple Incident - S1-E10
Continuity mistake: When Marshall gives Ted the phone to find out who's number is on his arm, he presses 2 buttons then gets through. No time to dial the number. (00:12:00)
Matchmaker - S1-E7
Continuity mistake: At the Matchmaker's office, when Barney is saying he just wants someone to hold, Ellen is seen putting her pencil down on the desk but in the next shot it is in her hand again. (00:03:50)
Sandcastles in the Sand - S3-E16
Continuity mistake: When Lily goes to the bar with her friend Michelle, Barney says "I want her around all the time." It then cuts from Barney to Lily's slightly shocked looking face, obviously from a previous cut/scene change, sitting at the table with them - she should still be walking to the bar with Michelle.
Suggested correction: Those were different days. Robin agrees to watch Simon's practice before we see Michelle the first time, then the scene cuts to Robin watching the band practice, then the news feed and then the next scene with Michelle. All the character's clothes changed indicating a different time.
Continuity mistake: The morning after the second party, the items on the coffee table change instantly between shots. Several beer bottles and blue cups vanish, whilst a red cup and red bowl appear. (00:11:00)
The Wedding - S1-E12
Continuity mistake: In this episode, Lily is in Robin's house with her dogs. In the episode "World's Greatest Couple", Robin reveals that Lily can not stay at her apartment because Lily is allergic to dogs.
Suggested correction: Doesn't mean Lily can't go over and visit for a while. My mother is allergic to cats. She can visit her cat-owning friends for a while, though she would never stay overnight. Pet allergies can be pretty controllable, as long as you're not constantly in contact with the animal.
Continuity mistake: When Steph is telling Ted that she used to star in adult films, we see her pick up the mini corn with her chopsticks from one angle, then the shot changes and she picks it up again. (00:02:30)
Continuity mistake: In the final scene at the bar, Barney is seen eating the olive from his drink and discarding the stick. A second later, when the shot changes, the olive and stick are back in his glass.
