This looks more like a carcass failure than a blowout since the sidewall separated from the thread. The separation is definitely a failure of some kind on the manufacturing process as driving on a flat tyre will never separate the sidewall from the thread as cleanly as yours did.

That would be the difficult part. We all know that the structure of the tyre is held together by the inner metal mesh and when that fails, the carcass would fail as the rubber can't hold itself together without the mesh. From your pics you can see that the sidewall is separated rather neatly from the tread. A single point of failure like a puncture will not cause that kind of damage. If you search for carcass / sidewall separation you will find quite of number of cases that looks like yours.

As you have posted that you heard a blowout, that would mean the entire sidewall separated at the same time. Unlike Hollywood, a single puncture or point of failure will not cause a tyre to 'explode' like in the movies.