WHY:
A very good question indeed:
Is it my imagination in looking at one of the photos to see what appears to be a "smoke" haze about the fuselage and rear gear area?
Secondly, when doing aeros, I was taught to wind in a bit of nose up trim, just so as you had to push positive on the stick, and if you blacked out in a high G, then the A?C should recover with a decreased G load while you recover.
Now if this happened as in the photo, almost inverted: and at such speed!
Food for thought maybe?