Continuity mistake: The driver of the gas tanker kicks around frantically as Doomsday is ripping him out of the truck and kills him. His foot goes through the driver's side of the windshield, shattering it. But the passenger side is unharmed because it is a separate window in this model of truck. The truck plows through the guard rail after Doomsday kills the driver and plummets to the ground, the passenger side of the windshield still fine. But in the shot of it just before it hits the ground, it is suddenly cracked as well.
Picture added by Quantom X