Road Accident

One car driver is driving on his side of road. From front another car is coming from front. Suddenly a motocycle starts overtaking the latter car. To avoid certain head on collision with the motor cyclist, first car swerved to HIS RIGHT and brakes fully. Wearing a seat belt, nothing happens to him. Meanwhile, front car stays at same speed. Both car right bumpers collide and get damaged. At the same time the overtalkin motor cyclist moves to furtheer right but not enough so collide & damages his bike and left side of bumper of 1st car. Falls down and hurt himself and pillion. The case was reported by 2nd car owner. 1. Who will investigate? 2. By the way, 1st car owner told the hurt guys looking from poor background that he will take care of all medical expenses, motor cycle repairs, if not insured which is likely! And any compensation as desired. That time he agreed. They were promptly admitted to hospital and both hospital authorities and hurt party told that 1st car driver will pay all expenses! 3. In the meantime other car driver pressed charges and FIR in ABSENCE of 1st driver. Both cars coficated by police. Question 1. What are liabilities of all 3 parties on legal front? Question 2. The incident occured at 6.30 pm. 1st driver had one beer b4 lunch at around 3 pm. On asking the doc, hhe was told it's difficult to predict, if blood sample will show traces of alcohol or not. As depends on person to person. Is their some permissive limit of alcohol! I was told so in Pune during NEW YEAR EVE. That pegs permitted. More than that please take a driver. Doc wrote *appears he had a drink without any breath analyser* is that valid legally? Will it change status of the case. Driver age 52 , driving since age 20. No accident record in 30 + years! Regards Ajay