This is where the story went stupid for the sake of the plot...
How in the hell did that guy get away with this? Literally stand on top of the place throwing a ball (?) at the car causing accident!!?? His finger print is all over that ball. Plus, anyone driving behind the crashed car can see a man throwing stuff at the car in front. Plus, polices in Japan are not stupid, that front windshield clearly showed sign of being hit...
Plus he is the prime suspect due to motive, no? And still, he managed to work in law afterward? In a society like Japan?