My Old Friend's New Friend - S4-E1
Continuity mistake: When JD writes 'Al Coholic' on the shifts board and the shot then cuts to Elliot, there is a brief cut back to JD and you can see behind him that his prank name has changed to 'Dr. Ass Face'.
My Old Friend's New Friend - S4-E1
Continuity mistake: At the end, after Carla and Turk drive off in their new car, JD is on his scooter and there isn't a chain attached to its rear. But when he drives off there is.
My Old Friend's New Friend - S4-E1
Visible crew/equipment: When JD and the Janitor are having a conversation outside the hospital, on the giant X, crew members are reflected in JD's helmet when the camera is facing the Janitor.
My Old Friend's New Friend - S4-E1
Continuity mistake: Right after Elliot asks Molly about the patient, you can see the Janitor standing next to the table behind Molly. But in the close-up shots on Molly, he is gone.
My Old Friend's New Friend - S4-E1
Continuity mistake: In the end, when Carla comes out of the hospital and sees the Mini Cooper, JD's hands changes between shots. In one of the far shots he is holding the handles on his scooter, but in a close-up shot he is holding his helmet.
Answer: No, it was a fake, they used a stamp.
It is real.