A Therapist, a Comic Book, and a Breakfast Sausage - S1-E4
Continuity mistake: When Connie is talking about her date possibly wanting some more of her, George Jr. has a fork in his hands. When the shot changes, his hand is at his mouth without a fork in it. (00:04:55)
A Therapist, a Comic Book, and a Breakfast Sausage - S1-E4
Continuity mistake: When Tam moves his stuff on the lunch table, his arms are around his lunch. When the camera does an instant cut, his arm is no longer around his lunch. (00:03:30)
A Therapist, a Comic Book, and a Breakfast Sausage - S1-E4
Continuity mistake: When Sheldon points out how big the sausage was that he choked on, he holds his hands up in the air to symbolize this. From the shot behind Sheldon, his hand is not visible. (00:03:00)
A Therapist, a Comic Book, and a Breakfast Sausage - S1-E4
Continuity mistake: When George Sr. is first trying to help Sheldon, who is choking, he has his left arm under Sheldon's body. When the shot changes, his left arm is across the back of Sheldon's neck. (00:00:40)
A Computer, a Plastic Pony, and a Case of Beer - S1-E12
Continuity mistake: Sheldon pinches a loaf of bread, but a shot later he's pinching spaghetti. This changes back and forth a couple of times.
A Computer, a Plastic Pony, and a Case of Beer - S1-E12
Continuity mistake: When the family leaves the computer store, Missy's candy sucker swaps randomly between being in her mouth or not between one frame and the other.
A Solar Calculator, a Game Ball, and a Cheerleader's Bosom - S1-E5
Continuity mistake: When Connie is playing the slot machine at the end, the wheels land in a set order. She then has a chat with someone and then goes to spin again, but the wheels are in different positions than before. We see Connie through all of this, and she doesn't spin between the two instances outlined here. (00:17:30)
A Solar Calculator, a Game Ball, and a Cheerleader's Bosom - S1-E5
Continuity mistake: When George Sr sits down to talk statistics with Sheldon at the kitchen table, his beer bottle keeps rotating in his hand. Note the label. (00:08:30)
Visible crew/equipment: When Missy runs through the house at the start the stage lights are reflected in her sunglasses. (00:02:25)
Rockets, Communists, and the Dewey Decimal System - S1-E2
Continuity mistake: When Tam mentions the Ku Klux Klan, Mary has nothing on her fork. When the shot changes, she's suddenly got some food on her fork. (00:15:40)
Continuity mistake: At the start, the cards in Sheldon's hands keep changing between shots. (00:00:40)
Answer: Some people just have a dislike for someone that can't be explained. Could be as simple as the way he's dressed.