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.
Answer: It was in "Chaos Theory", the first episode of season 9 (time code 00:13:55).
Super Grover ★