I think it is trees that block the view ob the lower part of the fireball. But the general statement is true: one can only see a small (upper) part of the fireball.
What else can be drawn from the way the fireball and the parts spread is that the angle of arrival was rather shallow, maybe somewhere around 30° and the forward velocity was very high.
So no lumbering in a stall and no lost tail feathers either.
Looks generally like a loss of control at altitude for whatever reason followed by an (aerodynamically) controlled (but from a piloting perspective apparently uncontrolled) dive with insufficient altitude to recover.