A time lapse shows stars setting into the skyline. The editing makes the Sun seem to rise in the opposite direction.
When Paul Gross' character first visits the village to speak with the elders the translator speaks in Dari and the elder responds in Arabic. Arabic is not spoken in Afghanistan. He should be speaking Pashto.
In the dancing scene, waiting for a call, a local says they are listening to "Leif Garrett", some have correctly identified the song as "Play That Funky Music" but misidentified the artist as "Wild Cherry". It is in fact the cover by "Leif Garrett" that is playing.
When Paul Gross's patrol arrives at the safe house to meet with the Ghost for the first time, the first Afghan National Army (ANA) jeep has a .50 cal machine gun on the roof, but it's obvious that it wasn't attached as it's on its side without ammunition belt. The actor tries to right it when they stop.
At the start of the movie the squad is in a good hide below the ridge line. When they move out the shot shows them walking down the top of the ridge perfectly silhouetted against the blue sky. It looks cool but soldiers would try not to present themselves as such a clear target. They would continue to move below the brow of the hill so as not to skyline themselves.
General Rowlin ("99") swears far too much for a general officer - this may have been written into the script for entertainment value.
Although it's plausible, it's highly unlikely at the ending ramp ceremony that 39A and G9W (Gross) would have issued berets with the leather band. Their characters would likely have bought their own berets at this point in their career.