Factual error: In the Swamp, Dr. Wu says "maeu gamsahabnida" when taking out the needle. It was translated as "Dr. Wu says the treatment is completed." The correct translation is "thank you very much"
Suggested correction: This is taking the dialogue too literally. Translating culturally specific terms and forms of expression into something the counterpart can understand in the intended way is entirely appropriate and only logical. A person not familiar with English culture would be very confused if, for instance, someone translated the phrase "Your goose is cooked" literally.