Factual error: Jimmy Langley wears the single pip of a second lieutenant. He was actually a lieutenant at the time and should therefore be wearing two pips.
Factual error: Harold Alexander, although his rank of major-general is correctly mentioned by the narrator, wears the rank insignia of a full general.
Deliverance - S1-E3
Factual error: The crosses marking the graves of British soldiers outside the hospital abbreviate Private as the American "Pvt" rather than the British "Pte."