What we know:

Two gliders taking part in a competition collided
It was mandatory for all gliders flying in the competition to have FLARM
fitted.
One pilot survived and sadly, one died.

What we do not know:
What the flight profile was at the time of the accident, thermalling,
straight glide or final glide. (There has been much discussion of the
abilities of FLARM in a thermal but no evidence that the aircraft that
collided were thermalling)
The status of the FLARM devices, were they fully operational or in
Competition or Stealth mode or indeed working at all.
We do not know what warnings may or may not have been given to the pilots
and suggestions that competition pilots may ignore warnings in a
generalisation that I would find insulting if I were a competition pilot.
I am a competition director and I can say that most of the competition
pilots I have met are responsible and safety concious. Many things can
spoil your competition chances, having a mid air certainly will, so to
suggest that a pilot may ignore warnings is illogical.
What I would be interested to know is whether or not the status of the
FLARM units had any significance in this accident. I have expressed grave
doubts about degrading the performance of FLARM, even by a very small
amount, and the consequences of such action. I suspect that it may be some
time before the information is available.
A final thought, gliding is not dangerous in the same way that driving is
not dangerous per se. What a minority of pilots do can be dangerous and it
is up to all of us to ensure that if a pilot is dangerous he/she does not
get the opportunity to continue to be a danger to thers.