Broken Pedal Possible for Buick
Obviously if the pedal snaps off, the engine will return to idle.
On some 2016 Buick Cascada and 2012-2017 Verano vehicles, the accelerator pedal can break at the stalk just below the housing due to the driver entering or exiting the vehicle with their foot resting on the pedal. An improved pedal is available as P/N 13252702.