Sam writes down one of the plate numbers as TYP-7497. It's later shown being entered on a monitor at Command as TYP-7479.
In earlier shows, Gerhardt (Max Martini) was an E-8 Master Sergeant. The final episode he is shown as an E-7 SFC. Also, Brown (Scott Foley) was promoted to an E-7 in an earlier show and the final episode he is shown as an E-6 SSGT.
In "Pandemonium, Pt 2" (3-2), Jonas Blane identifies himself as a Command Sergeant Major, however, in "Unknown Soldier" (4-22), Jonas is seen in his dress uniform wearing the rank insignia of Sergeant Major, which differs from the rank insignia of Command Sergeant Major in the US Army (Command Sergeant Major has a wreath surrounding the star in the center of the chevrons.) He also does not appear to be wearing Command Sergeant Major (branch immaterial) collar brass.
Mack's rank has always been Master Sergeant but he was wearing First Sergeant stripes at the wedding.
Mack, a Master Sergeant, is seen with the rank of a Sergeant First Class on his Dress Blues in the final scene. This could be the result of a Season 3 story line in which he was suspected of abusing Tiffy, however, Soldiers in the Special Operations community are generally released from such assignments and returned to the regular Army for such instances of wrongdoing.
Jonas says he discovers a Bluetooth device on the bomb so that it can be detonated by a cell phone. However Bluetooth is for connecting to devices nearby and it's not triggered by a cell signal.
When in Craighead County, Arkansas we see an Arkansas Highway Police car but the officers are wearing Arkansas State Police uniforms. While Arkansas Highway Police are part of The Arkansas State Police, they wear different uniforms.
During the car chase in Arkansas you can see palm trees in the background. Palm trees are not native to Craighead County.
Early on, Sergeant McBride addresses Sergeant Major Blaine as "Sergeant". No Sergeant would ever make that mistake, and no Sergeant Major would ever let it pass.