#3...yes, looking at the film several times, it could be a slight quartering tailwind, but maybe the guy has minimal tailwheel time, as indicated by the control surface deflections, as also mentioned by RR, so was not prepared for the landing and rollout.
His technique was then , shall we say, not quite right for the given conditions.
But the main thing, was nobody was hurt, and there was an engineer to say, under no circumstances fly it home.