I once had a miscreant working under me that was constantly stirring up trouble behind the scenes and laughing from the sidelines when the **** hit the fan. He stretched all the rules to the limit but was clever enough to make catching him breaking them tough. He was using several drugs, making him erratic.
He was also on a "last chance agreement" over having failed a previous drug test, and had to take a drug test because he had an industrial accident, soooo he purchased the urine from an associate, because his was still messed up.
Alas and to our joy and amazement, the associate that took his money's urine was also seriously messed up, including heroin, so our miscreant lost his last chance agreement.