fire hydrant???
Your arm can travel more than 24 mph and the car still weighs the same. You would also have bruises, no matter which way you did it. Also a backing vehicle that could have enough momentum to shatter like that by hitting his arm would also make impact to other parts of his body and the tail light pieces would all fall near the point of impact, not scattered all over the yard and road. If you want to say they followed him, there would be fragments embedded in and on his clothing, yet there were none AND no tissue or blood on the pieces. It simply did not happen that way. Physics prove this. Very simple physics, at that. For those pieces to fly like that, there is no way for her to only be traveling at 24 mph. In a high speed impact, sure.