I have quite a few hours in the back seat of a Puchacz, and like some
other posters suspect that the story as related to Cindy is somewhat
suspect. For example:

On Saturday, following only a few flights, the pilot felt some
restriction in rudder movement, and asked the front seat passenger
to adjust the length of rudder stirrups for more freedom of movement.
The passenger complied, and free movement was "restored."

Altering the front pedals merely lengthens or shortens the cable
connecting front and rear pedals - the cable which actuates the rudder
runs from the rear pedals to the rudder fittings. The only restriction
this change could affect would be that of the front pilot's feet on
the pedals.

Also the Puchacz is not strongly directionally stable even with the
rudder attached. With it missing, I'm sure the glider would have been
wallowing around the sky and clearly have felt utterly wrong, even
when attempting to fly straight. If:

The flight continued in nice lift, and some mild maneuvers
for perhaps twenty five more minutes prior to landing.

without a rudder, the pilot must have been flying in boxing gloves not
to notice something was very wrong.

I'm not saying the rudder didn't fall off, but I don't find the
"decorative" parts of the story convincing.