A car accident is a traumatic event that can send you into a state of confusion and/or anger. When you are confused and/or angry, then you may do things that you wouldn't normally do when you are calm and prepared. As a result, angry drivers that have just been involved in an accident can make rash decisions such as fleeing the scene or getting so upset with other people involved in the crash that a confrontation occurs.
You should avoid these outcomes at all costs. Fleeing the scene of an accident makes you a hit-and-run driver, and now your car accident - which may have purely been an accident originally - is a crime. In the other scenario mentioned above, if you argue and confront other people involved in a car accident, it is possible for things to get out of hand.
Instead, you should take a deep breath after a car accident and prepare to deal with the aftermath.
Now, it is important to note that we are talking about mild to moderate car accidents where the participants are okay and able to get out of their cars and walk around. In more serious accidents, you should call 911 as soon as possible.
In these milder accidents, you should take pictures of the scene and the vehicles involved. You should also talk to anyone who witnessed the accident. If they are willing to go on the record, then get their contact information and their account could be used in any lawsuit you may file at a later date.