That was a new AS-350BE (Airbus) that has a twist grip throttle that can bring the engine to idle and stop such rotation. It appears that full Nr was in effect the whole ride and that the pilot was keeping it level with cyclic (small movements and centered). All new production AStars have a poor mans CVR/FDR factory installed (Aperro) that could/should tell the story. Dollies are a high risk convenience with bad risk/reward ratios. Dollies take up hangar space, inhibit inspection, and can be deadly with a control or power problem on TO or landing.Bird comes with ground handling wheels, stick em on and push. Dolly caused this accident. Astars are the most difficult bird to put on dolly pads as PIC sits way forward of skids and often will land short if not trained properly. AS350 will ground resonance easily and has features to mitigate this tendency but a bouncy pad can negate the engineering. I fly a 2B1 Astar from a small pad for the last 5 years and know it is a bad idea but can't fight an ignorant city hall (management).