In this episode, O'Rouke has lent the Hakawi the Troop's cannon for their MOON FESTIVAL and they won't give it back. However, in the establishing shot of the Fort coming back from the commercial, the cannon can clearly be seen sitting in it's usual spot next to the flag pole in the Fort compound.
Col. Donnely says he expects an "18 gun" salute for Gen. Grant when he arrives at the fort. There has never been a practice of a salute with 18 guns, as the normal number would have been for 21. While lesser dignitaries might receive fewer guns, the number of guns used is always an odd number and would never be an even amount like 18.
Agarn (pretending to be General Ulysses S. Grant) says that he had lunch at the White House with President and Mrs. Lincoln the day before arriving at Fort Courage. There is no way Grant could have made the trip from Washington to Kansas in one day. Also, by the time Captain Parmenter arrived at Fort Courage after receiving his medal after the Battle of Appomattox, President Lincoln's assassination would already have taken place. At the time of Lincoln's assassination, Grant and his wife were in Philadelphia.
As Col. Donnelly prepares to leave, he salutes Capt. Parmenter, turns his horse and rides out of the fort. A colonel would never salute a lower-ranking officer first; the captain would salute the colonel, the colonel would return the salute and then ride off.
Cpl. Agarn, while impersonating Gen. Grant, tries to impress the Hakawi by reminding them that he won at a great victory at Gettysburg. However, when Gettysburg was being fought, Grant was actually at the siege of Vicksburg, about 1,000 miles away.