The societal implications of technology developed through physics research are not always clear. Physicists need to use ethical reasoning skills to maneuver through morally ambiguous situations. For this reason, curricula for physics students should also be geared towards developing these skills. Research can be found on the effects of structured ethical discussions in similar fields like engineering education, however, little research can be found on their effects in physics education. Our research focuses on how students interpret and apply an ethical framework to discussions about the development of the atomic bomb and to current STEM research. Our preliminary analysis shows that students conflate certain ethical principles and/or avoid their negative implications, which in turn leads to a misapplication of the principles. However, students also demonstrate a range of productive approaches to applying these ethical principles which contribute to the development of strong ethical arguments.