The reason to the car accident
Car accidents and stopping distances are affected by the conditions on your brakes and tires, your cars conditions, the quality and condition of the road and of course also by the weather. Everything affects both timing faults and also positional faults. Sometimes it's hard to deduce whose fault it is and other times it is much easier.
Keep calm and analyse the accident
If you understand stopping distances in different conditions and different speed. Then you can also estimate the distances between the cars when the accident happend. Sometimes a driver gets into wrong position or location on the road and sometimes because of bad timing. All of this happens really fast, so by keep you nerve at all times you can avoid a lot of extra trouble.
Never get into argument with the other party
Let the police you are calling handle the accident and if they haven't arrived. Don't move anything unless there is traffic problems and traffic jam. Even if the other driver is behaving irrationally, don't follow in this person's footsteps. Never retaliate in some way. Just gather information as much as you can and then wait until the police arrives. So with other words, you should call the police after a car accident.