Factual error: The Marines in Afghanistan in 2003 are seen wearing MTVs (Modular Tactical Vest), when in reality they should be wearing IBAs (Interceptor Body Armor). The MTV was adopted by the Marines in 2006 to replace the IBA. Lance Corporal Coughlin (Evan Jonigkeit) is seen wearing an IBA but none of the other Marines are.
Factual error: When Kim Baker arrives in Afghanistan, most of the Marines are seen wearing Desert marpat (Marine Pattern), when in reality, that camouflage was not widely adopted until 2004 to 2005. In 2003, it was in the testing phases, Three Color Desert or DCU (sometimes called "Coffee-stained") would've been the primary camouflage pattern for both Marines and Army soldiers.