Don Johnstone wrote:

spiral dive. Which was obviously the case here.

I don't see that as obvious.

"Meanwhile, the glider quickly gathered speed until it exceeded Vne."
(Page 2 of the report.)

How did it get from spin
to spiral dive.

By itself. Just as many gliders do.

The question is was the glider ever in a spin.

I don't know (I'm tempted to say: nobody does) whether the glider was
technically ever in a spin or started right into the spiral dive. The
question is pretty pointless, pulling back the stick is a bad move in
either case.

Stefan