CTR: Never disrespected the pilots. Just stated the obvious that the test pilots in a monitored test environment are unwilling to push out to hit the planned test point. This points to serious loads or other safety issues not simply ride comfort.
Nige: The 525 accident occurred when the ship was well above Vne and the pilot failed to take action to correct rotor rpm droop within the planned response time after simulated engine loss. No traditional helicopter can survive flight above Vne with the rotor rpm decayed to 60% of normal operating rpm.
As to 609 the aircraft had been to the accident speeds and above without incident before they reduced the area of the tail. Also new flight control software to improve high speed stability with the smaller tail had been finalized, but not installed on the fatal flight.
Back to the 97 it was marketed to be physically impossible for the rotors to collide due to their stiffness. This was always thought to be a questionable claim especially when the size grew above the X-2. Collision of the rotors at flight rpm for any reason invalidates the concept. As stated in the NTSB report the control input rates were greater in the accident, not how the rotors were fundamentally controlled.