Factual error: When the man is brought into the ER after an encounter gone wrong with a dominatrix,Susan checks one eye and announces 'Pupils are equal and reactive' then proceeds to check the other eye.After checking one eye there is no way she would know that the patients pupillary reaction was equal.
Deliberate mistake: When the two lawyers were wheeled in by ambulance riding on the same gurney entered the ER the male had a bandage on his foot because they had been walking on hot coals. The hospital staff smelled smoke coming from the bandage on the male lawyers foot. It burst into flames and Abby used a Dry Chemical Fire Extinguisher. Something other than powder came out because the dry chemical powder would have made a large cloud of actor choking dust all over the set. The use of a C02 would have been a better choice. You would still get the fire fighting effect with out the mess.
Revealing mistake: Gallant is watching over some duck eggs that are about to hatch. At the end of the episode, two of the ducklings have hatched and Gallant is showing them to Carter and Susan. An unhatched egg falls out of Gallant's bundle and smashes on the street.The smashed egg has a large yellow yolk and clear fluid, like an egg in a grocery store. But an egg that close to hatching would have almost no yolk remaining and an almost fully developed duckling inside.
Continuity mistake: Inside the first 10 minutes, Greene finishes a trauma and his shift and heads upstairs to take Ella from Corday, so she can start her shift. Next, we go back down to the ER, where Benton and Finch are assessing a trauma victim. In the background you see Greene checking an X-ray film, but he has meant to already leave with his baby.
Continuity mistake: Chuny tells Abby that Weaver is looking for her because she didn't call Child Services for a patient. Abby then goes to a phone to call. While she's on the call she hands Malik some sporting event tickets. The next scene shows Weaver out on a date when she bumps into Malik and Susan on their way to the sporting event. The very next scene is back in the ER where Abby is telling Carter that Lewis (Susan) just discharged a patient. The scenes don't line up, as they give the impression that Weaver, Malik and Lewis are all on shift at the hospital, when they're out on the town at the same time.
Character mistake: Carter tells the mother of the smallpox infected children that no one has seen smallpox for 50 years. The episode aired in 2002, WHO didn't start its global eradication of smallpox until late 1950's and the last case was reported in 1978, which is only about 20 years.
Other mistake: In the opening sequence, there is an aerial shot where the camera pans over Central Park in New York City. The trees are full of leaves and some are changing color. The problem is that it is February when this episode is taking place, and the trees would have no leaves left on them.
Character mistake: In the season 8 episode 'Never Say Never,' In the opening scene before the credits, Dr. Susan Lewis returns to the ER to meet with Mark Greene for lunch. She is standing at the admit. desk and asks Frank, then Luca where she can find Dr. Green. The shot then pans out to a view of her back, exposing the curtain areas. In that shot, Dr. Green walks right past her, no more than 10 feet away. Due to their angles, there is no possible way neither of them would have not seen each other at that moment, yet he walks past, and she continues her hunt for him. (02:15:20)