Factual error: The picture of Eddie and Teddy on the road with dad, supposedly taken in 1906, shows a Ringling Bros and Barnum & Bailey circus poster. In 1906, the Ringling Brothers circus and the Barnum & Bailey circus were two separate circuses playing in different parts of the country. They did not combine the two shows until 1919. (00:27:00)
Factual error: When Billy The Kid is taking a bath and dictating a letter to Doc, intended for the governor, he says he is in the Mexican village of Juarez. This town was actually named "Paso del Norte" at the time, it wasn't until 10 years after the events depicted in the film that it was renamed "Ciudad Juarez."
Factual error: When Jack is trying to buy the bus tickets, the bus company employee tells him that his credit card was cancelled. Credit card companies do not divulge that type of information, they simply indicate whether the requested charge is accepted or denied.
Factual error: There is no way the DMV will pass one twin based on the fact that his twin passed, even though they ended up taking his license. The mistake was giving it to him in the first place based on the fact his twin passed.
Factual error: Sean Connery's character is the Provost Marshall for the Presidio, he would not be wearing the MP sleeve placard as he is in the scene at the Officer's Club. He also wouldn't be running around wearing a Field Jacket with the collar up and it unzipped. You wear the jacket correctly or not at all.
Factual error: Poirot meets the rest of the cast at the port of Trieste before they sail off for Jaffa. In actuality though, they already were in Jaffa, which served double duty acting as a very poor stand-in for Trieste; the architecture of the port and promenade is nothing like Trieste's, and you can see in the establishing shot Jaffa's St. Peter's church. (00:08:30)
Factual error: In cooking class, the teacher said "two stalks of celery" and Michael handed Lorna one stalk, which she started to separate. One "stalk" is actually the entire bunch (or head), which is made up of 8-10+ "ribs" connected at the bottom. Two ribs will equal about one chopped cup - about right for the tuna walnut casserole made with one can of tuna. Americans typically use the word "stalk" interchangeably with "rib", calling a single rib/ stick/ branch a stalk, but the stalk is the entire bunch. (00:37:02)