I'm sorry I misread your original post you said "unopened pack of cigarettes"? Like the cellophane was still on it? That doesnt make any sense. I'm still siding with the cop on this one though. Your son and his cousin are in a better position to distort the truth when telling you the story.
With that being said. Yes cops can be dickks, but a blemish on the record like that sends the flags up.
And cochran, that lawyer bullsht wont do anything but get you deeper and deeper into crap. That "I know the law" lawyer mentality is as wrong as a cop who oversteps his authority.