ok, now heres a question,
lets say, at 2 am one day, you get a phone call from a friend drunk and stoned off her nut... she despirately needs a ride home, and, asks you for one, which you grumblingly give her....
you go to the place (its a common friends house) to get her, go inside, and the smoke is so thick you can cut it with a knife. Quickly grabbing your bud with a minimum of breathing, you take her home.
Do you think that the picker-upper would test positive?