Character mistake: The 4 brothers have just rode into town and are securing their horses. On the flag pole in the background the Texas flag is upside down. Note: The correct way is white flies on top and red on bottom.
Character mistake: When Angelo sets the Vulcan down in the sea, he blows the canopy and extends the landing gear. As the plane settles, he attempts to release his harness, then has his air line cut by Largo. He futilely beats on the harness release when all he had to do was pull the face curtain handles to trigger the ejection seat, which would not only blow him clear of the plane but would separate him from the seat itself. Having trained for two years for this specific mission, he would undoubtedly be familiar with ejection procedures.
Character mistake: Ryan's final diary entry says the US Cavalry fought against "French irregulars." The French lancers were actually regular troops.
Character mistake: As Torrey's launch heads for his new flagship, a signalman calls to the quarterdeck that the admiral's party is arriving. However, the signalman gets his signals mixed, addressing his message to the signal bridge from the quarterdeck, instead of the other way round.
Character mistake: Lucy refers to fear of cats as "ailurophasia", which is incorrect; fear of cats is called "ailurophobia."
Character mistake: Liesl sings "I Am 16" with Rolfe before she is ever taught to sing "Do Re Mi" by Maria. We are led to believe the children have no concept of singing, so how was she able to sing this song before learning to sing? (00:41:00 - 00:42:00)
Suggested correction: They certainly know about singing. It's just been banned in the house since their mother died. Liesl, as the oldest, would have had the most experience of it.
Character mistake: Gregory Benson has shot a duck for dinner. It is hanging from a rope inside the back porch so it can age before being cooked. After Patti Randall's cat gets in the house and takes the duck, an enraged Gregory confronts her about her thieving cat. Patti later explains to her sister Ingrid, who had heard the commotion, that the cat had taken a duck from Gregory's "back porch", but Gregory had not told Patti where the duck had been hanging.
Character mistake: On a pillar in the department store, there is a sign saying "Bear, Tiger, Zebr Skins." It should read "Zebra."