While shooting a documentary, if you capture an amazing moment...
...turn it into a storyline.
By this I mean: capture a beginning, middle, and end.
And this person happens to be charismatic.
And they're telling you all about their point-of-view about some event.
If the footage you're getting is good, don't stop there.
Film at least two more scenes.
Structure a beginning, middle, and end.
So, for example, I might ask to film a re-creation of what they saw (or claimed to have seen).
Then continue following them for another hour, just to capture some verite documentary stuff.
Or revisit them some time later, possibly at a different location - and do a followup interview.
The most basic unit of storytelling is the beginning, middle, and end.
Think in terms of beginning, middle, and end & you'll always be on the right side of history!
So be on the lookout for unexpected storylines.
It's usually these meandering, diversionary subplots that end up becoming the most memorable part of a documentary.