Holding that the NLRB has the authority to interpret CBAs in the first instance where its interpretation is for the purpose of “enforc[ing] a statutory right which Congress considered necessary to allow labor and management to get on with the process of reaching fair terms and conditions of employment”
Holding review of the Board's decision to apply a new rule of law retrospectively is deferential and that the Board's ruling will be disturbed only if it wreaks manifest injustice
Holding that an employer is prohibited "from altering contractual terms concerning mandatory subjects of bargaining during the life of a collective bargaining agreement without the consent of the union"