Microburst is intersting suggestion! However, I would have expected to see that reflected in movement of the bushes next to the road, and I do to see that in the video. An exploding tire is the strongest hypothesis up to now.
Ken reports it as a downward thrust a tire would be a one side rocking, the lateral air flow to reach the bushes would occur seconds after the initial event the video has moved forward from that position so would not necessarily been seen.
