Revealing mistake: Near the beginning of the show, Mark's father puts a bulb into an old slide projector. Then there is a small explosion with smoke and flames - watched carefully, we can see are actually coming from the other side of the projector - the flames can be seen shooting parallel and close to the floor, which wouldn't have happened if the explosion actually came from the projector.
Continuity mistake: When Carol and Carter are discussing the overdose patient with nurse Dory, Carter's crutches change position and then return to their original position, even though no one adjusted them.
Continuity mistake: When Carter leans his crutches against the lockers in the lounge, we can see two pictures taped to his locker. However, after he picks his stuff up off the floor, the pictures have mysteriously disappeared.
Continuity mistake: When Carter goes into the lounge, he leans his crutches against the lockers and then moves his bag off his shoulder. One crutch falls to the floor, then the bag, then the other crutch. When the shot changes to show these items on the floor, the bag is lying neatly on top of the crutches - an impossibility due to the way they all fell.
Continuity mistake: Luka is in talking to the first possible kidney transplant patient - he puts his pen into his pocket and is holding the chart in his other hand, also up by his chest. As he says "Minneapolis", the shot changes and we see him put his pen in his pocket again and his chart is down by his waist - there was no time for the shift.
Continuity mistake: As Luka talks to the kidney patient, he is holding his chart to his chest. But several times during the scene, when the shot is on the patient, his hands are at his waist, but at other times they are folded in front of him.
Continuity mistake: When Carol and Luka are sitting in Wrigley Field she has a Diet Coke can in her hand. But when she goes to stand up, she leans down and picks up the can of Coke from the floor - even though at no time did she put it down there.
Continuity mistake: After Carter pulls the IV out of the patient who was allergic to sulfa, Malik asks, "Where's all the blood coming from?" and we see the patient's arm outstretched, bleeding from where the IV was. Carter says, "She must have pulled the IV out", and we see her arm folded up over her stomach - there was no time for the change in position.
Answer: It was in "Chaos Theory", the first episode of season 9 (time code 00:13:55).
Super Grover ★