A lead assessor is evaluating a multinational manufacturing firm\'s adherence to the principles outlined in ISO 26000:2010. The firm has publicly committed to environmental stewardship and fair labor practices. During the assessment, the lead assessor discovers that while the company has robust environmental policies and a dedicated sustainability department, the operational integration of these policies into the supply chain management of its raw material suppliers, particularly those in developing economies with less stringent regulatory oversight, appears superficial. Furthermore, employee grievance mechanisms, while present, are perceived by a significant portion of the workforce as bureaucratic and lacking in timely resolution, especially concerning issues related to working hours and overtime compensation. Considering the holistic nature of social responsibility as defined by ISO 26000:2010, what is the most critical deficiency the lead assessor should highlight in their report regarding the firm\'s social responsibility performance?