
Continuity mistake: When Sheldon is putting his mittens on at the table he his seen putting the first one on and the second one is on the table, the shot changes and the mitten is no longer on the table. He raises his hands and both hands have mittens on them. (00:01:55)
Answer: Some people just have a dislike for someone that can't be explained. Could be as simple as the way he's dressed.