Continuity mistake: Near the end, when Elizabeth and her mother are having wine, in one shot her mother has put the glass down on the table, but in the next shot, from behind her, she has the glass in her hand again. There was no time for the change.
Continuity mistake: When Cleo and Mark are playing basketball, when Mark shoots for the first time Cleo is standing to the left of the hoop - when the ball hits the rim it launches off the rim to the right, but in the next shot Cleo has the ball.
Continuity mistake: When Abby gets bitten she holds her wrist but in the next shot her hand is covering her upper forearm.
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.