Norfolk Southern overlooked alternatives and “compromised the integrity of the vent and burn decision by withholding complete and accurate expert opinions and information from the incident commander,” Stancil said. He noted that representatives of OxyVinyls, the company that manufactured the vinyl chloride onboard the train, repeatedly told the railroad that there were no signs of polymerization in the tanker cars, but that assessment was not relayed to the incident command team.

“The pattern of dismissing contradictory evidence while interpreting ambiguous evidence in support of Norfolk Southern’s and its contractors’ original belief was consistent with confirmation bias,” he said. “Whatever the underlying explanations were for the continued support of a vent and burn action, none justifies failing to communicate accurate and complete information, including dissenting expert opinions, to the incident command.”