Accident the day he bought Moto no insurance

Hi, my son (18 years) is depressed because he had a motor accident with a car, he sold his new N max Yamaha (less than one year of use) then added it to his first ever salary to buy T max (used) . He insured the T max casco partial, means that his insurance pay damages of others. The accident happened when a man crossed in front the car that precedes him suddenly. Car driver stopped his car accordingly while my son was trying to pass the car. I wish I can help him to fix this situation, but I can't because of a lot of financial commitment I already have. We need your help!

Due to the severity of the situation, we did not take pictures of the accident. The owner of the car and his wife were angry, my son was in this situation for the first time. The owner of the car attacked my son and demanded that he sign the papers immediately while he is still on the ground in pain.