What model forklift was this? If it had an inching petal, that you use your left foot on, they should have been able to control any movement even if the throttle was unintentionally pressed. I saw this happen when the operator with huge feet didn't have his left foot in position ready to go on the inching petal and his right foot got jammed up on the throttle and he went flying backward and put the counterweight through a wooden 2X4 wall. It was operator error.