Is the first driver, who struck a man in the middle of a fast international road at a permissible speed, liable for any blood money or expiation after an unknown truck struck the deceased man?

If the truck driver and the first driver caused the man's death, then each of them is liable for the blood money (diyyah) for accidental killing and its expiation (kaffarah). If the proportion of each one's contribution is known, then each is liable for what corresponds to his contribution. If the proportion is unknown, then they are jointly liable for half of the diyyah and kaffarah, equally divided. The driver is not responsible if the accident was due to an act of God (force majeure), or to the action of the injured party himself, or to the fault of another. There is no liability on the drivers if they did not commit negligence or transgression. If one of them was negligent, he is liable to the extent of his error.