Audio problem: When Greene is outside by the river explaining what happened to him, there are a couple of really bad sound edits in the background noise. These are really obvious as the sound suddenly changes, and for some reason the background noise in this scene is very loud, almost as loud as the dialogue; very strange.David Mercier
Continuity mistake: Within the space of what would appear to be more than 5 minutes in the ER, considering the continuous flow of action (starting with Kerry offering to get Pablo a taxi and ending with Dr. West examining the patient Lenny) the clock goes from 10:30 to 6:20. Shortly after that Dr. West pronounces Lenny dead, saying 13:38 (or 1:38).
Other mistake: When Doug and the nurses are watching the TV about a motorcycle accident, Kerry comes along and calls him Mark. This could be a character error, but as Doug responds 'yeah', and they talk, it indeed becomes a production error. In real life, the person would have corrected her. (00:07:15)
Continuity mistake: Near the beginning of the show, Doug is examining baby Josh and puts his stethoscope in his ears. Kerry says, "Your actions are totally irresponsible", and the shot goes to Doug. There is no sign of the stethoscope anywhere. The next shot, from behind him, shows it's around his neck. He then takes it off and the next shot should show it in his hands - but it's disappeared again.
Continuity mistake: Carter rushes over to a Coke dispenser where there are four plastic jugs filled with ice and we see him dump all four of them into a plastic tub. The camera goes to Anna, who says "Carter, Carter" and then we see him dump the last two jugs again. When Carter reaches the patient, there is considerably more ice in the tub than he had to begin with.
Continuity mistake: In the OR, Peter is trying to save Dr. Swanson's life. Lizzie is standing in the corner watching. She has her right hand up to her chin, resting the elbow on her left hand, which is at her waist. Subsequent shots show the opposite - her left hand on her right.
Continuity mistake: Lizzie sees Dr. Morgenstern for the first time in the ER and she asks Kerry, "Who the hell was that?", and Kerry answers, "Our Chief of Emergency Medicine." Yet when he resigns in Episode 19, he tells Peter he's resigning as Chief of Surgery. Unless he held both positions, Kerry's answer could not be considered a character mistake, as she would have known what his position was.
Continuity mistake: Even though Carter and Henry were outside in the snow when the patient Lenny arrived, and they had quite a bit of snow in their hair, when the shot goes to them entering the building, we don't see any snow on Carter and Henry - but there is still lots on the patient and the paramedics.
Continuity mistake: The paramedics bring Lenny by ambulance and are taking him out of the back of it - Carter picks up the chart from the gurney as the paramedic describes the patient - but suddenly the chart is back on the gurney - we should have seen Carter do this but we don't.