After a little research on the net, I found that a condom filled with urine is the method of choice for passing (pun intended) a drug test. When asked to come in for a drug test, the adventurer doomed to failure gets a clean and sober friend (if they can find one) to urinate in a condom and tie it off. Then they hide it in their pants.
When asked for the sample, they prick the condom and produce the squeaky-clean sample. I suspect this one got away from the person who needed to take a drug test, and they had the good judgement not to stoop to pick it up.
Amazing what the Internet brings us.