From the facts that you have written if one causes an accident and does not within a reasonable time stop and assist at the scene but rather continues on down the road, what is described is a "hit and run" situation which is a criminal act.However, if the person returns to the scene within a reasonable amount of time then possibly the conduct would not fall within the statutory definition of a "hit and run". What is a resaonable amount of time to return is decided on a case by case basis of each accident.The consequences for a hit and run could be a criminal charge, conviction, jail, fines and a permanent criminal record.