The OSN's that Bell issued mentioned that on one occurrence the pilot stated that he did not have both feet on the pedals during cruise flight at 120+ KIAS when the aircraft started the rapid yaw. That's probably where the presumption of full pedal inflight comes from. Sounds likely. It appears that the pedal stop has solved the problem.
The original thread is a question about the negative delta 3 on the 407 tail rotor. "Helisphere", if you're still out there, the delta hinge minimizes flapping by taking the tail rotor natural flapping frequency away from resonance with the aerodynamic frequency. The natural frequency is 1 per rev, aerodynamic loads are 1 per rev. A negative delta reduces the natural frequency to less than 1 per rev, positive delta increases it to more than 1 per rev.