yeah i dont think they will actually watch "from source to destination" as they sometimes refer to it, although i had a friend whom was given a random drug test not for suspicion or anything, that was just procedure. He told me that a clinic employee went onsite, they informed him he was going to have to submit a sample, only had like a 35 minute advance notice and the guy went with him into the bathroom (this bathroom was the several enclosed stalls setup) and the guy was just outside the stall with the stall door closed, but in the bathroom with him nevertheless.
By the way employee positive, how exactly did u pull off the substitution you spoke of?