Plot hole: There are always family members right in the room while the doctors are literally cutting into the patients. The family is always creating a fuss or whatever, until someone asks for them to escorted out. A real hospital would never let family members into the room while they are cracking open their loved one's chest.
Plot hole: During Season 5, the search for an ER Chief takes nearly a year and two nationwide searches, but is ultimately unsuccessful. At the beginning of Season 6, Romano is chosen as Chief of *Staff* in the blink of an eye, and Kerry is appointed as ER Chief just as quickly. Then, in Season 9, Kerry and Romano's positions are switched as though such things happen everyday. There's no way decisions of this magnitude would be made in such a brief amount of time.
Deliberate mistake: The show regularly shows characters by the Chicago River and either on or near Michigan Avenue, when they are getting lunch or walking to work. Both U of C hospital (where the hospital exteriors are filmed) and Cook Country hospital (where the characters are supposed to work) are about 5 miles from this point. This would be an extremely long distance for them to walk on a routine basis. I'm sure this is done just because Michigan Ave and the river are two of the most scenic parts of Chicago.
Factual error: Featured characters in the show always seem to be wearing brand new winter clothing - their jackets, hats, gloves, etc. always look pristine, sparkling clean, and just-purchased. Anyone who lives in a winter climate knows that winter clothes age very quickly - the pristine look last about an hour. Extras in the show, probably providing their own clothes, wear much more lived-in normal outdoor clothing.
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.
24 Hours (1) (a.k.a. The Longest Day (1)) - S1-E1
Visible crew/equipment: When Hathaway tells Ross and Greene there are no more patients, the two doctors are standing in the corridor, and you can see their tape marks on the floor for where they need to stand. (00:11:15)
24 Hours (2) (a.k.a. The Longest Day (2)) - S1-E2
Visible crew/equipment: When Dr. Greene goes into the lab with Mrs. Raskin, the boom mic is reflected in the glass behind them.
24 Hours (2) (a.k.a. The Longest Day (2)) - S1-E2
Visible crew/equipment: After Peter examines the man with a ruptured aortic aneurysm, he exits the room. Peter tells Susan that this man needs immediate surgery, and in the shots facing the exam room during their conversation, we can see the reflection of the moving boom mic on the door's glass, at the top of the screen.
Visible crew/equipment: Carter is told about the multiple rectal exams due to food poisoning. It then cuts to admitting, and just as the person at the desk bends over, on the glass partition we can see the reflection of the boom operator (wearing a white T-shirt) holding up the boom pole (not the maintenance worker standing on the ladder).
Going Home - S1-E4
Visible crew/equipment: While Doug and Carol are talking outside, Carol says, "You think you had something to do with my swallowing a whole bunch of pills," and just as Carol continues, "Well, you didn't," in this shot facing Doug, the boom mic dips into view at the top of the screen.
Going Home - S1-E4
Visible crew/equipment: After Lydia tells Carol that she's there if Carol ever wants to talk about it, just as Lydia hugs Carol, the reflection of the boom mic swoops into view on the partition, at the top right corner of the screen.
Going Home - S1-E4
Visible crew/equipment: Carol stands at the admitting doors and quips, "Excuse me, I'm here to unload that new shipment of barbiturates." It then cuts to Jerry and Susan just as they see Carol, and there's a director's chair, with "Script" on its back (for script coordinator), visible at the right side of the screen.
Hit and Run - S1-E5
Visible crew/equipment: After Malik brings in the bolt-cutters for the handcuffs on Mark's patient, it then cuts to Peter examining Susan's patient, and we can see the boom mic's moving reflection on the glass window.
Visible crew/equipment: Right at the start, Hathaway wakes Ross and Carter from their naps, and as she says, "Carter, med students don't sleep at 4:00 in the afternoon," there's a visible boom pole/mic at the top left side of the screen, that gets pulled up out of sight when the lights turn on.
Chicago Heat - S1-E7
Visible crew/equipment: After Dr. Benton talks to the police detective and then goes to see the grocery store owner, as Dr. Benton swings open the doors, the camera crew can be seen in the reflection of the glass of the door.
Chicago Heat - S1-E7
Continuity mistake: Near the start of the show, Carol is on the phone in the ER - we can see her name tag pinned over the right side of her stethoscope. In the next shot, as she turns to talk to Mark, the tag is pinned over the left side of the stethoscope.
Chicago Heat - S1-E7
Continuity mistake: As Doug Ross sits with the little girl Kaneisha who is sleeping, her bedcovers change position noticeably in one shot, and then back to the way they were in the next. In the same shots, Doug's ID also changes from being completely noticeable to almost completely obscured, and then back again.
Continuity mistake: When Susan and Chloe are fighting in front of the desk, you can see 2 marks on Susan's right shoulder that look like blood with no obvious source from previous scenes. While Chloe is having her hand treated, Susan is standing outside the door and turns, and the marks have disappeared. (00:35:05 - 00:35:50)
9 1/2 Hours (a.k.a. Growing Up) - S1-E9
Visible crew/equipment: Susan leaves Mr. Randall on the elevator and tells him to call a cab so he can go home. When it cuts to Walt working on a car just as Peter shows up, the boom mic pops up into view and proceeds to bob around at the bottom right side of the screen.
9 1/2 Hours (a.k.a. Growing Up) - S1-E9
Visible crew/equipment: While Peter, Susan, and others start working on the high school wrestler, when a nurse says, "Glucose normal," and also in following shots, the reflection of the moving boom mic is visible on the door's glass, toward the top left side of the screen.
Answer: A man named Paul Sobriki comes into the ER in the season 6 episode 13 " All in the Family." He is complaining of headaches, Carter and Lucy decide to rule out meningitis and do a lumber puncture. Paul struggles during the procedure and believes that both doctors are stabbing him. Lucy, who is interested in Psych thinks something is wrong with their patient mentally, but Carter is dismissive of her. She gets cross with his attitude and she calls the psych department anyway to have a look at him. Later on and near the closing 20 minutes or so of the episode, all the staff start playing loud music and get a cake which appears to be blue lol, together to party as it's Valentines Day, Carter returns from somewhere and asks where Lucy is. He goes to check one of the rooms for her and Paul Sobriki comes up behind him in the dark and stabs him twice in the lower back, he collapses and as he falls unconscious he sees Lucy on the ground also. In the next episode, Be Still My Heart (ep 14), Dr Weaver discovers them and all of the staff work to try and save them, whilst Carter survives. Lucy's wounds are fatal and suffers a pulmonary embolism as Corday and Romano try to save her. Carter is grief stricken and feels guilty about the way he treated her, he becomes addicted to painkillers and Benton, Greene all help him and book him into rehab.