Producer Nigel Turner used dramatic reconstructions with actors to portray the covertly recorded conversation between right-wing activist Joseph Milteer and police informant Willie Somerset on 'TMWKK' because the original surveillance audio recordings were either inaudible, structurally fragmented, or legally/technically unfit for direct broadcast.
Original 1963 police wire/surveillance recordings of Milteer were muffled, degraded, and difficult for general television audiences to understand clearly without enhancement or re-reading.
Using voice actors allowed the precise, controversial text of what Milteer stated regarding threats against President Kennedy to be presented coherently to the audience.
There is nothing unethical about that as long as it is clearly labeled as a DRAMATIZATION.
Likewise, in the early days of covering the space program, the networks would often simulate space maneuvers because the technology did not exist to show the actual event, but they always labeled those as SIMULATION.
ABC's Cokie Roberts was once suspended for her coverage of the State of the Union Address when she did a report wearing an overcoat while standing in front of a picture of the Capitol Building while in the ABC studios. There is, or at least there was, a strict code against faking a news report, even for something as benign as what Roberts did.