Madman? We have the results of controls, we do not know the pilot's intentions.
I have listed several reasons the a/c may not have been purposely directed to the attitude and altitude it reached. Until they are eliminated, it seems rather like piling on to assume this pilot was a madman, bent on STALL. Do you actually believe that was his intent?
His initial inputs may have been inadvertent in Pitch.
Banging on the drum only identifies a lack of circumspection, imho.
I have never heard of a pilot in UAS commanding such a climb.
There are three instances where the a/c did it on her own, in similar. There are also warnings (post 447) not to re-select a/p when speeds return. "The a/c may climb without command."
Do you see this?
I'll wait.