After a mine worker tested positive for cocaine twice, he got treatment and was allowed to return to work on certain conditions, including random testing. He tested positive again in a random test. Then he disappeared for four days and left a disturbing message on his supervisor’s phone. When he came back to work, he attended a meeting where he acted suspiciously. So he was asked to take a drug test, which he failed. The mine fired him and the union filed a grievance. An arbitrator ruled for the mine. Whether there was reasonable cause to ask the worker to take a drug test was irrelevant as he’d agreed to random testing. And that test was again positive for cocaine. Also, the worker’s explanation for the positive test—that his wife had slipped cocaine into his medication—was “unusual” and unsupported by any evidence, added the arbitrator [Vale Canada Ltd. (Manitoba Operations) v. United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union, Local 6166 (Unjust Termination Grievance),  M.G.A.D. No. 8, Nov. 20, 2015].