Problem: Considering this, "A 25-year-old young man is dropped off by a friend at the emergency department (ED) and states that he was in a motor vehicle accident 30 min before arriving. He says that his car was extensively damaged but that he was able to get out of the car and walk around at the scene. There was no loss of consciousness. He states that the police were at the scene investigating. He does not volunteer whether the police questioned him personally or why the police let him leave. Except for bumps and bruises, he is not significantly injured enough to justify a radiograph or computed tomography scan of his head. However, I detect the odor of ethanol on his breath, and so I order a blood ethanol to evaluate his capacity Copyright Oxford University Press. All rights reserved. Unauthorized reprinting or distribution is prohibited." what does this case study involve?