Personally, I don't understand why certain people would be against the way the documentary was produced, hating Benita's narration (why she talked throughout).
Making Benita the primary witness was undoubtedly a better approach to establish a sense of rapport. Nobody could provide us with a better insight than her as she was almost his wife. This has helped to clarify Paulo's identity beyond his work as a surgeon.
It is really unbelievable how Paulo can lie to practically anybody. When he revealed to Benita that he was actually a sniper and was an undercover doctor, I nearly burst out laughing. These little things mattered just as much as it made us feel how it was like to be with a guy like Paulo. The question of why SHE was chosen by Paulo instead of all the other ladies out there is answered by the fact that she was A journalist!