When Griff (Barry Sullivan) is being set-up by Charlie Savage (Chuck Hayward), Charlie can see Griff's shadow beneath the window, with Griff still out of sight. But the street-level scene shows Griff's shadow behind him, back into the alley.
During the opening gun play by the drunken ranch hands in town, the telegraph sign in the window is shot out. After the fracas is broken up, Griff goes to send a telegram and the window and signage is unbroken.
When Jessica Drummond goes to visit her brother Brockie in jail she states she can't help him because he killed a United States marshal. The man he shot, Wes Bonnell, actually took the job as City marshal which is equivalent to a police officer. When Wes informed his brother Griff he was taking the job he discussed the pay difference with a federal marshal position. When Brockie had earlier shot the former City marshal, John Chisum, in the leg Jessica had no trouble getting him released so there is a distinction between the two jobs.
When Griff and Wes go out the the Drummond ranch to arrest the deputy sheriff, Griff has a conversation with Jessica. She asks to see his pistol and while she's handling it she states that it could have seriously hurt her brother Brockie when Griff hit him to arrest him. Griff borrowed the pistol he used when he went to arrest Brockie for the shooting up the town and wounding the City marshal and did not use his own pearl handled silver plated pistol. One pistol is probably about the same as the next when you get hit in the head but Griff doesn't correct Jessica's incorrect assumption and statement.
When the gunsmith is fitting Wes for a new rifle, he is holding the stock from a model 1898 Mauser, which would not be invented for another 20 years. Wes also picks up a Winchester and looks through the barrel to see the lady gunsmith, which is not possible due to there being no straight line of sight through the action.