Goofs

During the poker scene a $100 bill with Benjamin Franklin's face on it can be seen. These types of bills first came out in 1914 weren't being made during the old west.

In the poker scene, Trinity offers Wildcat Hendricks a cut (time mark: ~38:15). Hendricks cuts the top half toward himself but Trinity places the top half back on top and deals, which he obviously did on purpose, but if Hendricks is a card sharp (professional gambler), he certainly should have noticed and acted immediately. .

In the first poker scene, after Trinity shuffles and the card sharp cuts the deck, Trinity picks up the cut half of the deck and puts it back on top of the rest of the cards (i.e., backwards). He did this on purpose to cheat so everyone would get good hands and bet big money.

There is a scene where neither can read or write. An X is used for a signature. Later they are reading wanted posters and more. (Although it is feasible that they simply looked at the pictures and the reward amounts.)

When playing poker, the first player bet 10. After he called the 100, he put in a 100 bill and took 50 back. He should have taken his original 10 back.