About that "if you smoked within the last 28 days..." im betting thats all bs! just a lie. cops do it all the time it happenend to me during my dui like 5 times, there not suposed to do it but its there word against yours, and there going to win everytime! since thats probably not the law (witch you need to check and see) it wont matter he just scared you, while trying to get you to admit guilt, like i said before, get a laywer!