So far you have "blamed" the accident on
lack of radio
the rudder signal
The lack of good instruction
the topilots' use of the signal

everything to divert responsibility away from the glider pilot and on
to something/someone else

By this logic, there's no such thing as a bad training program.

Assigning blame is off-topic.

It's not a question of blame. No one denies that the pilot is
responsible for all of his actions.

The issue is whether our national training program (as promoted by
SSF) contains an unforeseen flaw that is contributing to the accident
rate.