When Flagg smashes his cast with the x-ray machine: As he pulls down and it hits the cast it bounces back up; but the cast is crushed in the next shot (when watched in slow motion).
When Hoolihan exposes Col Flagg's upper arm to put on a cast, she gasps at a tattoo she sees ( to seen by viewer, as Hawkeye blocks the view). However, in the next shot, the viewer can see his entire arm, and there's no tattoo.
When Flagg (Stone, Queen Victoria) goes into the personnel files ahead of Pratt ( Carter) , the filing cabinet is unlocked. In previous episodes, anyone who wanted access to the files found them under lock and key.
Frank Burns mentions a Gary Cooper movie with the character Billy Mitchell. This movie came out in 1955. The Korean War ended in 1953.
When confiding with Col. Flagg in the Officers' Club, Margaret says that Frank has "kept a complete list of everybody in this camp who's ever been subversive or promoted ahead of certain other doctors just because they showed off by saving more lives." But this impossible because Frank arrived at the 4077th as a major, and the only one to outrank him has been Lt. Col. Blake, who established the unit at his present rank. So, as the 4077th's second-in-command since it was established, no one at the 4077th could have been promoted ahead of Maj. Burns.
When Flagg lists the main characters, in his report, he says: "Captain Benjamin Franklin Pierce. Captain John McIntyre. Lieutenant Colonel Henry Blake. Major Margaret Houlihan and Major Frank Burns. Corporal Radar O'Reilly." 'Radar' is a nickname. His real name is Walter O'Reilly. Flagg identifies none of the other characters by their nicknames.