When Elaine (Julia Louis-Dreyfus) gave her co-worker the Tic-Tacs, a rattling sound could be heard every time he walked around. However, the first time she gave them to him, there was no noise.
Although turkey does contain trace amounts of tryptophan, there isn't enough to put a person to sleep. The reason people associate turkey with drowsiness is that it is usually consumed at Thanksgiving or Christmas, when large amounts of food are consumed which generally wipes people out.
When George swerves to miss the pigeon, he is turning left, but they lean to the left. Due to the forces involved, they would lean to the right.
When the group are in Kramer's (Michael Richards) apartment 'on set', Kramer begins to eat the chips and Diet Coke, then burps. Jason Alexander can be seen struggling to hold back laughter.