When Turk opens the door for his brother you can see his coat hanging on the hook on the wall next to the door. The camera then cuts to J.D. and when it goes back to Turks brother you can see that the coat is no longer hanging on the hook. Then the camera goes wide to show all three characters and the coat is back on the hook. The camera changes angles a couple more times and the next time you see the hook the coat is gone again.