Re NZ 'burning' email
The only thing missing in the report was the actual time of observation (UT+7 for Vietnam, UT+8 for Malaysia)
Reading it, he obviously saw something burning and wrote burning (plane) to indicate he thought the burning could be a plane.
His bearing is basically due West. At the time of interest and given the duration it's unlikely to be a planet. It could be an aircraft at any distance depending on altitude.
The other alternative is a satellite. I've seen naked-eye satellites flare brightly and expand in size due to outgassing while in orbit. Alternatively I've also seen satellites re-entering that flared for about that period of time - tens of seconds. The only unusual thing is it was due west while satellites tend to orbit in an inclined plane, so no lateral movement is a problem for that explanation - though not impossible.