Supporting students’ sense-making in discussions and labs is an important goal of college physics instruction. In this study, we explore how students navigate the socio-emotional risks of collaboration during moments of uncertainty while doing a lab activity. Attending to sense-making in the video recording of one group’s work, we contrasted two episodes where the quality of their collaboration played out differently. We found that one of the group members changed how they navigated the tension that arose within the group from episode 1 to 2, going from disengagement to forceful idea-sharing, which increased the risk of disagreement in the second episode and hindered the group’s sense-making progress. This case study shows how different approaches to socio-emotional risks could lead to different conceptual results of group work, contributing another example to a body of work showing how achieving our objectives for collaborative learning depends on careful attention to students’ epistemological, conceptual, and socio-emotional resources.