"The features of the accident site and the degree and location of the aircraft damage were consistent with the aircraft being in an incipient or developed spin to the right at impact."
This sounds typical of a simple stall/spin accident. Unlike for the first departure, no mention is made of the speed during the unplanned go-around which had a low level turn at a weight that could have been close to maximum.
"They went through the same start procedure and ensured the trim was set fully forward with the slots locked for takeoff."
"They made a normal right hand circuit with the passenger flying and he unlocked the slots and set the trim for landing."
"The passenger released the control stick but followed through lightly on the rudder pedals and, during the takeoff roll he locked the slots."
I have flown a Moth with 'slots'. The only time I ever locked them was for practice stalls(never did aerobatics). Is it normal for some pilots to lock the slots for takeoff? wouldn't that increase the stall speed?