In S02E16"My Karma", Elliot says that she talks to her cats and sometimes they respond in her mother's voice. In this episode, Elliot says that all cats hate and freak out if they even make eye contact with her.
When JD opened his apartment door to his brother Dan, the latter tackled him into the apartment, leaving the front door wide open. It was not closing.
Then when Turk came in and joined the dog pile, the door was completely closed.
When Turk is putting on his chilled underwear, the thermos moves from left to right throughout the scene.