My Old Lady - S1-E4
Revealing mistake: When the old lady patient is seen "escaping" she lifts the walking frame up out of the hole and it catches the set and lifts it into shot.
My Old Lady - S1-E4
Revealing mistake: Just before all the bricks fall on JD and it's a surprise, you can see him flinch before they hit him.
My Two Dads - S1-E5
Revealing mistake: The third time Elliott exposes herself to a patient (this time to the dead one that Dr. Cox is about to pronounce), you can see quite plainly that she doesn't raise her scrub top enough to reveal her breasts. In fact, the shot is wide enough that if she had, her breasts would have been fully visible on camera.
Revealing mistake: When Elliot and JD are at the baseball nets, Elliot gets hit by a baseball. If you look closely, particularly in slo-mo, you can see that the ball goes behind her head, and is probably digitally removed from coming out from the other side.
My Journey - S3-E2
Revealing mistake: When Elliot is splashed by the dolphin, if you watch carefully you can see her hair is already wet.
Revealing mistake: The patient Dr. Kelso says is dead is actually breathing while lying there in the bed. (00:06:25)
Revealing mistake: J.D visits Danni's apartment to talk to her about Elliot. The guy who answers the door says 'I better put on some underwear' but when he walks away you can see that he is wearing boxer shorts.
Revealing mistake: When Dr. Cox is duct-taping Dan to the bathroom wall, you can see that the tape across Dan's forehead is already stuck before Cox sticks it.
Revealing mistake: When Dan is in the tub you can see his dark swimsuit in a few shots.
My Boss's Free Haircut - S4-E20
Revealing mistake: When Carla and Elliot are walking through the graveyard, Elliot falls into an open grave. After she has fallen off the bottom of the screen, you can see her ankle flick up in the bottom of the picture, showing that she actually just fell down on the floor during shooting.
Revealing mistake: In the scene where J.D. first starts the bike portion of the triathlon, you can see his feet pedaling. You can see that there is no chain on the gears, allowing him to exaggerate the speed he is pedaling.
My Way Home - S5-E7
Revealing mistake: 5-07 - Doug clobbers JD with the fire extinguisher when he's in the body bag. When JD asks him why and Doug explains with the fire extinguisher in his hands, you can see him flexing it and that it's made out of rubber.
My Big Bird - S5-E8
Revealing mistake: When JD is kicked through the window by the ostriches, watch the window. It fractures about a half a second before JD hits it.
Revealing mistake: When Kelso hits Dr Hendrick's bike with his car at the end, you can tell it is not Kelso. While you can't make out his face, you can see that the man driving has dark black hair, while Kelso has light brown/grey hair.
Revealing mistake: Watch the line appear on the wall as Kelso cuts through the wall into the "Luxury Suite." The line is being cut with a round, drywall cutting bit such as would be used with a drill or Dremel tool. You can see it spinning as the cut is made. However, when Kelso has pushed down the wall and points the tool at Cox and the Janitor, he is now holding a standard reciprocating saw with a flat blade which would cut very differently than what was shown.
Revealing mistake: Right after Dr. Cox gives the results of the patients STD tests, the shot switches to show Turk, JD, the Todd and Dr. Kelso. Before the sprinkler activates you can tell that their hair is already wet from previous takes.
Answer: No, it was a fake, they used a stamp.
It is real.