Continuity mistake: Near the start of the show, Dr. Dave asks the patient Jesse how he's feeling and Jesse answers, "Not so well", and then begins throwing up. By the next shot, though, there is more vomit on his shirt than could have possibly got there in such a short time.
Continuity mistake: After saving Mr. Perez, Carter says "That's a nice save" to Mark, and takes his stethoscope out of his ears and wraps it around his neck. The next shot, however, from behind him, shows the stethoscope is still in his ears.
Continuity mistake: When Mr. Perez pushes Carter into the window, Carter's stethoscope is around his neck with the earpieces on the right. At one point during the fight the stethoscope is around his neck with the earpieces on the left - and then returns to the other position.
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.