Nat Geo (8:55 - 8:57) & "The Full Darnell Film" by - "The JFK Theorist" (23:32 - 23:40)
Nat Geo - Shows the Elm St Extension to be empty of people. Amos Euins is sitting inside Inspector Sawyer's car and Officer Harkness's 3 wheel motorcycle is double parked next to Inspector Sawyer's Car. (Time Stamp)
"The Full Darnell Film" - Shows the Elm St Extension now jammed with people. Officer Harkness is filmed providing security behind the TSBD. (Time Stamp)
Yeah. About that:
The segment in the Nat Geo episode you refer to shows a DPD officer walking by in a blue hat carrying a shotgun. The blue hat marks the officer as a member of the DPD patrol division. The shotgun was issued to the guys manning patrol cruisers, and was carried in the cars. Security of the motorcade route was given to the white-hatted traffic division. The patrol division officers provided security in the Trade Mart, or were out on normal patrol.
What this boils down to is that the office you see in the Nat Geo snippet is one of the patrol officers sent to Dealey Plaza by the dispatcher, but they don't start arriving until 12:45 at the earliest. That is the very earliest the Nat Geo segment could have possibly occurred, and it was likely taken even later. In the end, it doesn't further your notions at all.
After 62+ years, I can understand you're having problems accepting that which has been right in front of you. But there it is, right there. The Elm St Ext is jammed with people.
Again, if you actually look at the Darnell film, you see that the crowd of people is south of where the ESX is already turned northeast. You can actually see a car parked on the north side of the ESX to the left of the crowd. That wouldn't happen if the street was as packed with people as you'd like to believe.
Also again, when Martin is filming Harkness driving Euins down the street, he is standing directly south of the TSBD annex. You can tell by how close the red gates are. That puts Martin to the east of where the crown in Darnell is gathered. The following image shows the area where the Darnell crowd was gathered in red, with Martin's position marked with a red lower-case "m".