Continuity mistake: When Carter picks up his crutches from the floor of the lounge, his hand is near the crossbars. When he hoists himself up, the shot shows his hand near the top of the crutches.
Continuity mistake: When Carol and Carter are discussing the overdose patient with nurse Dory, Carter's crutches change position and then return to their original position, even though no one adjusted them.
Continuity mistake: When Carter leans his crutches against the lockers in the lounge, we can see two pictures taped to his locker. However, after he picks his stuff up off the floor, the pictures have mysteriously disappeared.
Continuity mistake: When Carter goes into the lounge, he leans his crutches against the lockers and then moves his bag off his shoulder. One crutch falls to the floor, then the bag, then the other crutch. When the shot changes to show these items on the floor, the bag is lying neatly on top of the crutches - an impossibility due to the way they all fell.
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.