After Doyle crashes the Ford Thunderbird a stuntman runs from the car but he clearly has more hair than the actor playing Doyle.
In one shot of the boy while he's steering the school bus, the windshield wipers are switched on. They are not in the other shots.
The device causing the white Chevrolet sedan to flip is briefly visible.
The white Chevrolet sedan being pulled by Doyle's green truck obviously has a stunt driver inside of it as it breaks free and flips over.
The log that flipped the white Chevrolet sedan is briefly visible.