Yep that is the one Chevvron.
I was told it was a spin off a low cable break,as I posted above - I was in the Hangar when it happened and have never seen an accident report for it.I don't remember it being absolutely next to the launch point but not too far up the field - long time ago so I certainly would not argue with anybody about it.
I have always assumed that TT and the cadet were just on or just over the min cockpit load,no bomb fitted and TT could not get the nose down to prevent stall/spin.