The Mommy Observation - S7-E18
Factual error: Based on the length of Bernadette's skirt and the place she's standing, Stuart could never see under it.
The Hot Troll Deviation - S4-E4
Factual error: Howard's claim that characters in World of Warcraft can engage in sexual activities is wrong, also while there is a Bridge of Souls currently in the game, there is no way to get under it.
Suggested correction: I can only assume you have never played on a RP server? ERP is a big thing, some players even make gold from it.
Factual error: Sheldon has a rigid schedule. Halo Night is known to be on Wednesday night. Penny sleeps on the couch in Sheldon and Leonard's apartment. The following morning, Sheldon cannot watch Doctor Who on BBC America because Penny is sleeping on his spot on the couch. He states that he has been watching Doctor Who every Saturday at 6:15 a.m. The following morning should be Thursday.
The Vacation Solution - S5-E16
Character mistake: In Amy's lab, when she is complaining to Sheldon how she gave him the simplest tasks, and that they're still not done, Sheldon replies with how Einstein failed math because he wasn't challenged, and that it is the same case with him. Einstein never failed math. Sheldon of all characters should know that.
The Higgs Boson Observation - S6-E3
Continuity mistake: At the end, when Alex and Sheldon are at the apartment, when Alex says "she seems nice", there are two beer bottles on the coffee table. The camera goes to Sheldon, and when it returns to Alex, there is only one bottle.
The Large Hadron Collision - S3-E15
Factual error: At the very end of the show, Leonard and Raj arrive at the hotel, which is supposed to be in Geneva, Switzerland, to visit CERN. If you look out the "hotel" window, it looks like they're half way up Matterhorn, but in Geneva there are no big/rocky mountains anywhere near the city itself.
The Big Bran Hypothesis - S1-E2
Visible crew/equipment: When Penny is having a go at Sheldon and Leonard, there is a shot of some metal pans with stage lights visible in them. (00:12:30)
The Fetal Kick Catalyst - S10-E6
Factual error: When Raj, Howard and Bernadette are in the car, Raj puts on Batman the Animated Series to distract Howard from his back pain. Howard says "I'm in too much pain to watch cartoo-oh, this is a good one!" However, there is no way he could know that it's a good episode of the show because the opening theme song can be heard playing and the name of the episode does not appear until after it.
Suggested correction: He meant the cartoon is good, in general. Not the specific episode.
Nah, he was told right beforehand that it was Batman: The Animated Series. A nerd like Howard definitely knows which cartoon that is and that it's a good cartoon without needing to look at it.
The Relaxation Integration - S11-E3
Character mistake: When Sheldon is telling Leonard, Amy and Penny about how his voice is like a white James Earl Jones, he quotes the famous Darth Vader line "Luke, I am your father." This is an example of the Mandela Effect, that apparently even Sheldon Cooper is susceptible to. Darth Vader actually says "No. I am your father."
The Jerusalem Duality - S1-E12
Visible crew/equipment: When Dr. Gablehouser is giving his speech about Dennis joining them, stage lights are reflected in his glasses and his wine glass. (00:16:30)
The Cooper-Hofstadter Polarization - S1-E9
Revealing mistake: When Leonard and Sheldon are fighting near the end they bump into the wall, which visibly shakes. (00:15:40)
The Dead Hooker Juxtaposition - S2-E19
Continuity mistake: In the scene after the boys have followed the new neighbor out and Sheldon and Penny are left eating alone, the utensils Penny holds change from chopsticks to a plastic fork and back several times.
The Fuzzy Boots Corollary - S1-E3
Revealing mistake: When everybody is on their laptops at the beginning of the episode, you can clearly see in many shots that their screens are black. (00:01:20)
Other mistake: When Howard, Stuart and Sheldon are ringing the bells, they are ringing differently from the "code" (00:16:45)
The Cohabitation Formulation - S4-E16
Continuity mistake: When Penny is pouring water into the glasses on the table after first meeting Raj's sister. The level of water in the pitcher changes between shots.
The Herb Garden Germination - S4-E20
Revealing mistake: Sheldon's laptop has gone through several strange transformations throughout the series, but in this episode it takes the biscuit - it appears to be a Dell XPS with the back covered up, but the shot of Sheldon chatting only to Amy shows a Mac keyboard, with the laptop running OS X.
The Shiny Trinket Maneuver - S5-E12
Character mistake: The bird that Sheldon is afraid of is referred to in the scene as a "Blue Jay." In fact, the bird is a Black-throated Magpie. A Blue Jay is a little smaller, has a shorter tail, does not have the darker plumage, and can be quite obnoxiously vocal.
The Middle Earth Paradigm - S1-E6
Visible crew/equipment: When Sheldon is being asked not to embarrass Leonard, the stage lights can be seen in the pans behind him. (00:05:10)