At the dinner table, the wine glasses vanish and reappear several times as the camera angles change.
West mentions his concerns with giving a truthful report to their superior, Colonel Falk, at the end of the episode. The Colonel who receives the report is credited as Colonel Fairchild.
In the dueling scene, West and Jack are using sabers, but their fighting style is for foil/epee.
When they travel back in time Col. Vautrain is now wearing a Confederate uniform. He is wearing the rank insignia of a Captain, three horizontal lines, and not that of a Colonel, which is three stars.
In the very first shot of West as Act I begins, an airplane is visible in the sky just behind his left shoulder.
While mathematicians had been toying with the notion of dimensions beyond three since at least 1827, and popularized by Edwin A. Abbott's book Flatland in 1888, the notion of time as a dimension was not brought up until 1908 in a paper by Hermann Minkowski.
When West, Gordon, and Col. Vautrain go through the portal, the only one who changes significantly (i.e., gets younger) is Col. Vautrain.
When Jim and Arte travel back through the portal to there dimension the house is on fire. It would only be on fire in the dimension they left. Jim said there were no bodies inside but they died in the house in the other dimension.