Continuity mistake: In season one (Thanksgiving episode) and in Season 2 (his graduation) Carter says he has a sister. After these seasons when his family is very involved in multiple plotlines there is no sister.
Character mistake: When Dr. Keaton rushes back into the OR to take over from Peter, she moves forward, pushing the door open with her hands. No surgeon would EVER enter an OR this way-it would contaminate her hands. The proper way is to back into the room, keeping one's hands in the air and free.
Continuity mistake: The timeline makes no sense. Carter goes home early and is working out in daylight at home. Kerry needs to leave at 6pm and Mark has a hockey game at 8pm. Luka and Abby are out on a date, after dark, when they are mugged, next Mark is at the hockey game. But shortly after, Kerry is getting ready to leave when Carter comes back to finish his shift. After that, Elizabeth is back in the ER working. Nothing in this timeline makes any sense.
Continuity mistake: During the last 2 minutes, Jerry is patronizing Dr. Waver. As he walks away, you see Dr. Greene (who has not been in this episode until now) walk across the hall in the background. A few moments later, outside, after Dr. Carter finishes chatting with the fire chief, he bumps into Dr. Greene outside. Dr. Greene is on his way in for his shift starting in 5 minutes and explains that he is coming straight from the airport. (00:43:22 - 00:44:50)
Character mistake: This has happened a few times before on this show. At the beginning of the episode, they are having a very loud party in the ER. There is no possible way this could ever happen in a real hospital. Even during an extremely quiet period, which rarely happens at County General, it would be extremely rude and unprofessional for patients. There's no way Kerry would be OK with such activities.
Continuity mistake: This episode is an instant continuation of episode 13. At the beginning of the episode, Kerry is walking in and asks if Mark is still on. Carol says he left at 8 for a double date. However, in the last episode, Mark was already at a restaurant with Elizabeth and their parents when Abby pronounced a patient's T.O.D. As 19:19. (00:00:55)
The Letter - S8-E20
Continuity mistake: When Dr Greene opens his locker for the last time, the locker is hinged on the left. However when Kerry and Carter clean out Dr Greene's locker after his death, the locker is hinged on the right.
What We Do - S15-E18
Revealing mistake: Sam's mother is standing at an open window, smoking a cigarette. The outside of the window is covered with some sort of frosted glass or ice or something (making it pointless to have it open anyway). Two shots later, we see her close the window from a different angle. This time, the window is clear and you can see the brick building next door. (00:19:36)
Visible crew/equipment: When Chen and Malucci walk into Doc Magoo's, as the camera pans around to the others already there, the reflection of the moving boom pole and mic is visible on the wall/window. (00:30:20)
Revealing mistake: After Mark gives his father the keys and tells him to park the van, in a following shot when Elizabeth joins the gurney rush with Carter, as she's walking backwards there's a distinctive large bulge at the back of her waist from the mic transmitter. (00:10:55)
Visible crew/equipment: When Carol and Luka follow Robbie to the trauma room with his mother's body they both stop at the doorway to watch Robbie, then just as the camera moves from behind Carol and Luka to in-between them zooming in on Robbie, the reflection of the moving boom pole and mic is visible on the glass behind Robbie. (00:32:30)
Continuity mistake: When young Robbie stands at the doorway of the trauma room with his father's body, the green door to the back supply cabinet is wide open and the floor is relatively clean, but when Robbie stands beside his father there are changes such as that cabinet door is closed, and the floor is littered with used latex gloves, etc. Then the cabinet door is wide open again when Carol and Luka walk in. (00:31:45)
Answer: Take care of your dad.