So, given that it is alleged that the Germans have a far better record on
winch accidents than the UK, is there someone on here with a good knowledge
of UK and German practices to indicate where or indeed if there are
differences that might account for this.

I can think of various areas where differences might occur:
Glider pilot training on the winch:- amount of launch failure training etc
Winch types and driver training including professional or club member
operation of the winch.
Launch point control systems and personnel operating them - training etc
Airfield layout and operations inc quality of strip/grass cutting etc.

My main experience is of UK glider clubs so short of people available that
at times the wing runner is also communicating upslack/allout over his hand
held radio to the winch driver and generally controlling the launch so has
both hands occupied. He is in no position while running to be able to stop
running, find the transmit button and send a stop command in the event of a
problem.