Regarding the authenticity of the supposed video - here's a link to a photo sequence of the 1960's mid-air collision of an XB70 Valkyrie and an F104 Starfighter. Please note that as the Starfighter breaks up, spills its fuel and burns at altitude, there is a significant LACK of dark black smoke.
https://www.youtube.com/watch?v=nEP7niGqiNg