At the dinner for Mr Chamberlain, the Earl of Grantham is suddenly taken ill, and is diagnosed with a perforated ulcer. This condition would, however, rarely present with major bleeding as shown here, but rather with intense abdominal pain. He is taken to the local, very small hospital and operated on. In a telephone call to Mr Carson, the Earl is said to have undergone a gastrectomy (removal of all or part of the stomach). This is a major surgical operation, taking in excess of 1-2 hours, which would require resources far beyond those of this hospital, and would also not be indicated for these symptoms. The preferred procedure in a perforated ulcer case under these circumstances would be to close the perforation, which is a much smaller and less dangerous operation.
At the end Lady Edith is seen writing a letter as she leaves the library the recipient and address (Turkish Ambassador, 43 Belgrave Square) are shown very briefly on the envelope. However, it wasn't until 1954 that No43 became the Turkish embassy, up until then they would have been located at 69 Portland Place.
Lord Grantham is taken to hospital by an ambulance with "North Yorkshire" written on the side panel. North Yorkshire did not exist until 1974. In the 1920s it was the North Riding of Yorkshire.