In this case study, we report how a team of firefighters critiqued one of its member’s decisions to facilitate learning and process improvement. The study is supported by 500+ hr of ethnographic observations, documents, and 11 retrospective interviews, which captured how the team’s talk about the member’s decision shaped their interpretations of their own and others’ expertise—interpretations that ironically undermined learning. Constant comparative analysis revealed that these firefighters positioned themselves as experts by crediting either personal experience or technical knowledge and then discrediting the alternative way of knowing. We labeled this process epistemic denial. The process of epistemic denial was rooted in identity concern; specifically, veteran team members relied on personal experience and newer members relied on technical information gained from training to assert their expertise, and to devalue others’ expertise. The article concludes with recommendations for avoiding problems associated with epistemic denial in high-reliability teams.