If memory serves me right, there was a fatal accident with a SZD55 maybe a year or two ago which sounded very similar to what the British accident report summary states:
'During a towed launch, the glider was seen to climb rapidly. After disconnecting from the tow rope with a very high pitch angle, the glider rolled to the right and descended before hitting the ground in a nose-down attitude. The pilot was fatally injured.'
I cannot find the NTSB accident report for the accident in the US but it may be worth looking into it.

Uli
'AS'