That's a really dumb response. Yes, it relies on closing the doors to achieve supersonic flight too.
The Boom plane doesn't rely on afterburners at any point in the trajectory to achieve supersonic flight. So yes, you would be reading the comments incorrectly.
Maybe it did, or is it public that it didn't? A possible sequence (very typical in rocket failures) is: fire, engine failure(s), loss of control, rupture due to aero forces or FTS activation, explosion due to propellant mixture. Not all of these have to happen, but it's a typical progression. Before the days of AFTS the FTS activation would be pretty delayed.
Nope. That's definitely an explosion (source: I'm in the rocket business). However it may not be an explosion of the whole stage. Probably of the engine section.
The Boom plane doesn't rely on afterburners at any point in the trajectory to achieve supersonic flight. So yes, you would be reading the comments incorrectly.
Gosh this website is full of ignorant people.