I went to your “Busted” link and he’s trying to show that the radar showed the flight continued into and over Vietnamese airspace where it was “tailed” by another aircraft. It then “disappeared” in the South China Sea off of DaNang according to the link? That’s at variance with all previous information. What’s the source of his radar readings (if you know)?
I cannot speak to the Youtube poster’s credibility or that of his sources. I saved the info on that video back when initially posted - just in case it proved worthwhile down the road. Perhaps it’s not what it purported to be.