i think that's kind of the point, this wasn't just before hand, it was during shift. And you can do what you like in your home as long as it's out of your system before you get behind the wheel of a car or are put in a position of responsibility.
But how do you prove that? For the amount of time I've smoked and the amount I smoke it would show up in my system even if I didn't smoke for a week or two, even longer if they did a hair test. Am I not supposed to drive or work for that length of time?