Thanks a lot, Pip, for your very detailed reply.
After the sentence quoted above, the author mentions several filmmakers that used certain historical footage in ther movies (like Spielberg - Saving private Ryan => Robert Capa's Photographs of the D-Day Landing). Then he goes on as follows (this sentence might help us...I hope...):
"If history survives thanks to its iconic images, taken by newsreel cameramen, agency photographers, or even at times, by amateurs, these images are not simply reproduced, inserted or re-staged: they become newly contextualized, narrativized, sometimes they are explicitly shown to be faked, forged, staged, or due to accident and mistaken assumptions."
(btw: if anyone knows a good translation for "mistaken assumptions"..., because that's my second problem in this context...=> maybe "Fehlinterpretationen"??? Thanks a lot!)