(For me it's a safe bet that any film that Henry Kissinger consents to participate in will almost certainly ignore or even condone the long-term blood bath he helped engineer. There won't be much reliable history there, but but maybe there's some perverse entertainment value watching at war criminal Kissinger take another stab at assuming the mantle of wise elder statesman.)
But back to Kennedy's doc, I think Nick Turse sums up nicely when he writes in The Nation: "Americans interested in learning about the real American War—beyond a decontextualized micro-history of its last blunder-filled and outrageous moments—won’t find much of use in Last Days in Vietnam."
However beyond that, the archival shots of people rushing across the tarmac for refuge on taxing aircraft looked very familiar. Here's the clip from Last Days in Vietnam:
Now here's a very similar clip from the Brad Pitt 2013 blockbuster World War Z. In this scene Atarot Airport in Jerusalem is overrun by a sprinting zombie hoard:
For me at least it's hard to imagine that World War Z didn't crib those famous newsreel shots for it's own purposes. Of course the zombie apocalypse has served as a metaphor for a wide range of social anxieties, and a recurring theme is that of the failed state which dovetails nicely with the fall of Saigon. However the key difference is that fictional zombie apocalypses are usually a consequence of viral outbreaks, while the catastrophe in Saigon was mostly the making of U.S. political leaders in the 1960's and '70's.