Vietnam War newsreel

A newsreel plays of Australians on patrol in Phuoc Tuy in Vietnam..it appears to be being shown in a then-current affairs context, and in the time period of the show, contemporary with the show's debut episode.Probably it is a "4-corners" Episode.

the Australians were well out of Vietnam b4 the first episode of "Countdown" screened, what, late 1974 ? FFS, this was 2 years into the Whitlam government's term.
Saigon actually fell a few months later in 1975, ending the Vietnam War altogether.

This seems a gobsmacking basic continuity glitch, anyone researching a period TV show would know as a matter of common knowledge about the time-frame of things like Australia in the Vietnam War.