It appears that in the initial situation, the nurse leader failed to effectively manage a conflict between the two nurses within their team. The nurse leader could have handled this conflict better by taking a direct approach and addressing it directly with the two nurses. She should also encourage them to reach an agreement on how to best resolve their differences.
In situations such as these, where different perspectives are involved, this would have helped to increase understanding. This could allow them to find common ground, or reveal underlying problems that need to addressed individually such as resentment. Having an open dialog encourages individuals to accept responsibility and ownership for their actions, which will help build healthier relationships.