Brody comes back a Sgt (E5), then is later shown 2 grades higher as a GySgt (E7) during the various speaking engagements and at Langley. Later, when going to the ball he is back in Sgt (E5) uniform. In addition, when he's in his GySgt uniform, the hash marks (stripes on lower sleeve) are 3, which designates 12 years of service. In the Dress blues at the party, where he's 2 ranks lower, Sgt, he's also only showing 1 hash mark- designating having completed 4 years of service.
The Taxicab in front of Saul's house has a North Carolina phone number on the door, and a "city of Charlotte" placard inside, even though Saul lives within a short distance of the CIA HQ outside of Washington, DC.
Nicholas Brody's rank changes from Sergeant (E5) to Gunnery Sergeant (E7) and back within the series. However, his service stripes also change on his uniforms. When he is wearing a Gunnery Sergeant's uniform he has three service stripes on his uniform indicating a minimum of 15 years of service in the Marine Corps. While on his uniform as a Sergeant in the episode Achilles Heel he has only one service stripe indicating a minimum of 5 years in the Marine Corps. but less than 10. This is not possible though because he spent 8 years as a POW and was a Sergeant before this time, so he would have to have been in the Marine Corps for about 4-5 years before becoming a POW.
After Elizabeth's party, both of Brody's children are watching Ice Age. Brody asks, "What's wrong with the elephant?" but the section shown on TV, recognizable as the official trailer of the first movie, doesn't feature this character for the duration of the scene.