Nurse gives Lucy an IV, and Matt checks the bag, asking if perhaps Dr. Klein would like to start Lucy on tributaline before magnesium. Lucy becomes alarmed, and the nurse tells her that Dr. Klein ordered magnesium and Matt can leave her alone. Matt asks to speak to Dr. Klein personally and the nurse leaves to get him, casting a few annoyed glances at Matt on her way out. Lucy starts to freak out that Dr. Klein is giving her the wrong medicine and tries to pull the IV out of her arm. Nice going, Matt. Dr. Klein comes in and tells Lucy that magnesium is the right medicine in Lucy's case. He then reassures her that he, unlike Matt, actually completed medical school, so he knows what he's doing and could he speak to Matt outside? Lucy wants them stay in the room because she doesn't want there to be any secrets because even during a medical emergency she's nosy as hell, to which Dr, Klein responds that he'd rather save Matt the embarrassment of a "public flogging."
Matt and Dr. Klein move to a large waiting area that seems like a much more public place for a flogging than Lucy's private room. The two exchange medical terminology, and it becomes clear that Matt really does think he knows more about medicine than an actual certified, practicing doctor. Dr. Klein says that he made the right decision about Lucy considering that she has a mild prolapsed mitral valve, which I looked up and am sad to report is rarely a cause of death. ["I have it; so does, like, 15 percent of the population. It's about as serious as having an outie bellybutton, seriously." -- Sars] Because of this, Dr. Klein ordered the magnesium instead of tributaline. He basically tells Matt to back off, and leaves. I'm just going to assume that Lucy already gave Dr. Klein permission to share her medical information with Matt, otherwise what he just did would be very wrong.