I'll throw one in to the mix, forgive me if it is too easy.
Several WWII documentaries annoyingly use file footage of this aircraft instead of the Fi-103.
I don't know the answer, but going to take a guess. Since we are talking documentaries, Hollywood wouldn't have been tryiing to make other aircraft look like a VI, so I'm going to guess the documentary film makers might have used V-2 footage by mistake
Mike