Factual error: In the opening scenes, Arizona mistakenly says a child suffering from eminent liver failure is at risk for psoriasis, when the script called for the word cirrhosis. Psoriasis is a skin disease. Cirrhosis is the medical term for end stage liver disease.
Continuity mistake: When Meredith tries to get into the OR to see Cristina, Bailey walks over to the door to stop her, and they talk. But in the final shot of Christina, you can see Bailey's hands on her head, even though Bailey is at the door with Meredith. (00:30:00)
Continuity mistake: When Christina is in the locker room eating a packet of crisps, everyone comes in and she asks them if they have any decent food. In the next shot you can see she is now holding an opened bar of chocolate. Then in the following shot we actually see Meredith hand her a wrapped bar, which Christina then opens (and the previously opened bar is gone, of course.) (00:03:40)Hamster