Continuity mistake: When Jordan slides on the floor going under the closing door her hat goes off landing straight, and already beyond the door. When it cuts to her picking it up it lies on its side and is now on the other side of the door, for her to reach under and collect it.
Continuity mistake: When J.D. walks up to the table where his interns are sitting, Keith and Rex are fighting with their table knives and have them crossed. The shot switches to a view from the other end of the table and suddenly Rex's knife is on the table and he is facing J.D. but Keith's knife is up in the air as if he was still fighting with Rex. There is not enough time for Rex to put his knife down and turn to face J.D.
Continuity mistake: After JD has done the "Eliott got some booty" song they both walk through a door, a patient in a red dressing gown then walks past. He wasn't there before they started walking and wouldn't have had been able to get there in that amount of time.