Even beyond the normal, "the media is no soldier's friend" in the editing room they tend to be sloppy.
I am sure that our members have noticed in documentaries "flipped negatives" that suggest left handed versions of rifles, or unit markings equipment on film clips that didn't exist in the time/location in the narration.
In places where uniforms and terrain are difficult to nail down allows Syria footage to morph to Iraq, or Afghanistan to become the Golan, etc etc.
It is sloppy work or creative licence that does discredit to many documentaries as a viable historical reference.