Yesterday I flew my TH at the beach. I took off from the foam lid since the beach was rocky. I would hand-catch when done. I'd done this before and it went smoothly then. This time, when I caught the bird, I throttled down until the motors idled then reached for the red button to kill the motors. I probably fumbled the throttle stick a bit trying to hold the controller with one hand while finding the red button. Anyway, the motors went to full power. At that point, I'm holding an angry bird that wants to fly away in the worst way. I repeated the shutdown sequence several times but there was no response. I could not get the motors to idle. Finally, at full throttle, the motors stopped abruptly. I nearly dropped the bird as the forces I was dealing with reversed instantaneously. Yes, I have the latest firmware. Yes, I should have been using the harness on the ST16. But why would the bird not respond to my throttle down command? And why would it stop abruptly like that at full power?