My story is good.
The same thing happened to me. Nailed it at the lights and then the throttle jammed open somehow, car rocketed down the street, evetually switched it off and rolled to a stop. Upon inspection, the f**king trumpet from my GFB Bov had unscrewed, and jumped across the engine bay coming to rest under the throttle lever leaving it wedged fully open
I made sure I screwed it on extra tight afterwards. Seriously though, what are the chances of that?