I expected to see a landing out of this approach so I guess I don't see what the fuss was about. Anyone can do a steep descent to a go-around.
With 2000 hours in a C-130 we did steep approaches but not to that degree. Though I saw no action in Vietnam, it was routine when landing at a forward operating base when small arms fire was a possibility, to do a circling desending maneuver over the field to reduce the possibilty of small arms hits. A steep descent to a landing as shown in the video would be impossible without vectored thrust, as least in any aircraft I've flown. I think the procedure the guys use would be a circling descent described above and perhaps a steep descent to within about a mile of the runway then a normal descent to a landing.
Reverse thrust in flight was available on the DC-8 to increase descent rates with the low by-pass engines using the inboard engines and idle thrust only.
Probably a more effective maneuver to reduce altitude is flying in a slip or cross controlling. We did that in the C-130 to increase descent rates and though I won't admit to it, I've heard it done in the B-737 and Fokker F-28.