If a passenger is caught with a controlled substance, can the driver also be indicted?

You were riding with a person in your car and you didn't know that they had a controlled substance on you, you get pulled over your driving and it's your car. They search you and the passenger and you're clean but the pill falls out on his seat from his pocket. The passenger tells the officer it's theirs. They let the driver go on the scene and didn't arrest them. Can the driver be indicted later? They are claiming to send the driver papers. The driver works in the medical field and has never got in any trouble.