A train conductor for a slag train instructed the engineer to proceed onto the skimming tracks, where it ran over an expensive cable puller chain. The company fired the conductor, claiming he directed the train to proceed when the safety light wasn’t green. He claimed the light had been green at the time. The arbitrator found that the evidence proved that the light wasn’t green when the conductor directed the train onto the skimming tracks. So there was cause for discipline. Given the seriousness of the safety incident and the small margin for safety errors in this workplace, the arbitrator concluded that there was just cause for the worker’s termination [Vale Canada Ltd. v. United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union, Local 6500,  CanLII 37150 (ON LA), July 14, 2014].