Lt. Col Mitchell was presented the Medal Of Honor in a flashback, but there is no corresponding ribbon on his Class A/B uniform when he introduces himself to General Landry for the first time. Also, there is a tradition where military personnel are strongly encouraged (it is not a law or official military regulation) to render salutes to Medal of Honor recipients, regardless of rank, as a sign of courtesy and of respect, not only for the soldier who received it, but for the award itself, so technically, Landry should have saluted him when he entered Landry's office.
As Teal'c walks through a door on Dakara he is seen going through the door with his hands behind his back. In the next scene, he walks through the door again with his hands at his sides.
There is absolutely no way and for no top secret or any other reason would a LtCol present the Medal of Honor to anyone. The President of the United States would have presented LtCol Cameron Mitchell the Medal of Honor. By some unbelievable circumstances the President was not able to do so, it would have been the Vice President with the Chairman of the Joint Chiefs and the Chief of Staff of the Air Force present.
In the flashback, when Carter is presenting the Medal of Honor to Mitchell, she calls it the Congressional Medal of Honor. The official name of the award is simply the Medal of Honor, presented in the name of Congress. However, it is commonly called the 'Congressional Medal of Honor', even on the CMH Society's website.
The puzzle Mitchell and Teal'c found in the cave contains mirrored Hindu-Arabic numbers. King Arthur and Merlin lived in 6-7th century and Hindu-Arabic numbers were introduced in Europe much later - in 12-13 century, so the puzzle should instead have consisted of roman numbers used in Europe during the period Arthur and Merlin lived.
Daniel Jackson mentions a tomb discovered in Glastonbury thought to be the tomb of King Arthur. He claims the tomb was exhumed in 1298 by orders of Henry II, but Henry II died in 1189. Henry II did order a search for the tomb of King Arthur. (The legends were becoming more and more popular during the early years of his reign, and he was concerned about the prophecy that Arthur would return.) Following these orders, the monks in Glastonbury announced the discovery of a tomb in 1191, two years after Henry's death. The bones found there were then moved in 1278 to a new tomb, that was destroyed during the Reformation. However, the 'discovery' is widely believed to be fraudulent, used by the monks to raise funds for the Abbey.
Mitchell does not salute Landry when they first meet. Anybody reporting for duty would salute the senior officer, even if indoors and not wearing a cover (hat).