1) As stated in my post Vy is 60 knots for a Cavalon 915. Vx is 50 knots. 70 knots even better in case the engine fails at low height you have plenty of reserve airspeed to help stay in control when you are within the height/velocity curve flying a Cavalon 915.
2) Anyone that hasn't flown a Cavalon in a year has no business jumping into it and taking off. At minimum any prudent pilot would have taken, at minimum, a check ride with a instructor. A Cavalon is one of the harder gyros to fly and can kill a lazy or deficient pilot.
3) If he was trying an airplane style takeoff he has no business being PIC of a gyroplane. A gyro is not a fixed wing airplane.
4) "Rumor has it that he started the takeoff roll with the cyclic in the forward position and pulled back when he realized things were not going as planned." That demonstrates his lack of knowledge (rusty, forgot, applied fixed wing reactions) on how to properly abort a gyro takeoff. A proper abort is 1) engine to idle and 2) stick fully forward before the rotor rpms go below the green line to protect the rotor blades.
5) "I have seen him fly and he appears to me to be a competent gyroplane pilot." His actions and behavior suggest he let his skills and knowledge degenerate.
6) "With all the gyroplanes I have flown if I have too much indicated air speed for the rotor rpm the retreating blade will stall and the advancing blade will sail." That is true if you exceed Vne, Vne for my Cavalon 915 is 105 KIAS. The information so far does not indicate a Vne blade stall. It indicates a rusty pilot, making the wrong decisions, and violating his height/velocity requirements.
7) "The damage to his rudder bears witness to a blade sailing incident." No. It indicates a "bad" blade flapping, likely from a low airspeed with his rotor blades not coned up. Pulling back on the stick was an incorrect abort procedure.
8) I am also grateful he is not injured, but he exercised bad judgment. It is important to call these accidents honesty and as we see them.