So much duh in this clip.
The ethical line is crossed when the documentarian misrepresents behavior, or worse, intervenes to film misrepresentations (look up lemmings mass suicides).
In the editing room, as long as the final cut is true to the nature of the subject, who cares what order it was shot in or that one clip after another came from different days in the field? Or that foley is added to enhance the scene?
Rather than fighting this as “fake documentary” we should be fighting the steady creep of reality TV tropes into our documentaries.