Alaska Air Group, Inc. (NYSE:ALK) is taking legal action against a mechanics union over an arbitration decision that reinstated a mechanic who tested positive for cannabis. The airline argues that the arbitration board overstepped its bounds and made decisions not based on factual evidence. The mechanic, Gregory Chappell, had been terminated after failing a random drug test, but he denied consuming cannabis and claimed he unknowingly ingested THC at a party. Aviation safety expert Dr. Karlene Petitt has criticized the airline's actions and called for support for Chappell.