If you have an accident,do not flee the scene or else you may presumed guilty.Firsthand accounts usually do not support that allegation.If you're guilty,then you'll have to pay your fair share and should do so without resentment.But if you run,then if you're found you may be confined in jail or with a large bail until a court date,more or less like an ordinary Thai would be.Thai police generally do not get involved in personal disputes unless there is a threat of injury by one party or the other.The police are very hands off in interpersonal matters.If there are legal agreements as part of the conflict,then you should go to the police station