If you read any of the accounts, you see that the claim is that many people switched over to Welles right after the opening comedy segment and when a singer started. In that way they would have missed all the early disclaimers and tuned in right at the war.
Your argument is actually an argument for the other side. You need to at least understand what the point of contention is.
I watched the whole thing last night. I’m pretty sure those actors were from the time period - it just didn’t look like a re-enactment even though whoever made that had the foresight to include a black interviewee. The whole program has a bit of background about Orson Welles’ career (his daughter is interviewed) and Martian research as it existed at the time.
If it was from the time period, it must have been from a movie about the panic. Does such a thing exist?
That was my first reaction, too—which is a tribute to the production team (the lighting in particular looks “period”.) But if you watch this little three-minute video (called “Making War of the Worlds,” if the site re-directs to the homepage), you will see the same people being filmed in 2013 (presumably).
It was clear to me right away that these were actors reading from a script, but I did think that they might have been 1940s actors reading from a 1940s script! Again, the lighting, make-up, and costuming is quite good.
I still find this “documentary” to be something I’d expect to see on one of the schlock channels. Re-enactments are questionable in all contexts, but when not clearly labeled as such, journalistic integrity is absent. The fact that these particular producers present the “widespread panic” scenario as being unquestionably factual is another indication that they are working in the field of entertainment rather than in the documentary field.
(Good documentaries can be entertaining, but not all entertainment rises to the level of being documentary.)