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.
ER (1994)
1 deliberate mistake in show generally
Starring: George Clooney, Anthony Edwards, Noah Wyle, Alex Kingston, Parminder Nagra
Genres: Drama
Visible crew/equipment: When Dr. DeRaad asks Kerry if she knows Paul Sobriki she tells him to check the board, and as Kerry walks past the door we can see the reflection of a crouched crew member walking backwards, pulling a rolling microphone stand. (00:02:45)
Robert Romano: They're going to be looking for a sacrificial lamb, and I have to tell you, right now you're looking pretty wooly.
Trivia: It is finally revealed here that Dr. Weaver uses the crutch because of congenital hip dysplasia.
Question: What does Romano sign to Reece? (00:44:40)
Answer: Take care of your dad.