I had something similar once years ago. I was riding one of my old dirt bikes when a branch got under the throttle cable on a trail and stretched the outer cable jacket. It uncoiled it and pulled the cable to full throttle. The problem was that this beater bike had no kill switch and was to young and dumb to put one on it. It was a 125 and in third gear so it took off and I bailed. The bike drove up a huge old oak about 12 ft and kind of backfliped onto the ground. It was cool to see and the cable was the only thing damaged.
Sorry about your trike man.
'02 Honda 416ex - A seasoned blend of 11 herbs and spices
'04 Honda Recon - The yard machine and snow plow
'88 Honda CR250R - Another chapter in my torrid all terrain affair