The project manager should have analyzed the boundaries of the negotiations for agreement to prevent this situation. This involves understanding the company's policies on core working hours and negotiating a schedule that aligns with the team member's needs while adhering to organizational norms. By doing so, the project manager could have ensured that the alternative working schedule was acceptable within the company's framework and avoided scrutiny from other teams. It's important to balance the flexibility required by the team with the expectations and standards of the broader organization.
References: While I can't provide direct links to the specific documents, the principles outlined here are in alignment with the PMI's standards and guidelines on project management and negotiation within the context of organizational policies and stakeholder management.

According to the PMBOKGuide, an agile team is a cross-functional group of people that is self-organized and empowered to deliver the project objectives. The agile team should have the following characteristics1:
* They are collaborative and work together as a cohesive unit
* They have generalizing specialists who can perform multiple roles and tasks
* They are co-located or use effective communication tools to overcome geographic barriers
* They are adaptive and responsive to changing requirements and feedback
* They are empowered and accountable for their work and decisions Therefore, the best option for the project leader is to choose a team whose members have more general aptitudes and can collaborate on different tasks, as this aligns with the agile principles and values. References: 1 PMBOKGuide, 6th edition, page 21.

In a project team, it's crucial to maintain a positive and collaborative environment. If a team member is being isolated, it can impact the team's effectiveness and the project's success1. The project manager should take proactive steps to address this issue1. Arranging and conducting team-building exercises can help improve team dynamics and integration1. Obtaining feedback from the isolated team member can provide insights into the situation and help identify potential solutions1. Similarly, getting feedback from other team members can help understand the root cause of the issue1. These actions can help the project manager address the issue effectively and ensure a positive and productive team environment1. References: 1 How Project Managers Can Deal With Difficult Team Members1