Labor law claim dismissed on revision; reversal of appellate judgment upholding defense against employee's demand

The Federal Labor Court (BAG) reversed the lower court rulings, dismissed the plaintiff's claim in its entirety, and ordered the plaintiff to bear all litigation costs, thereby allowing the first defendant to prevail. The dispute concerned a labor law claim filed by an employee against two defendants, where the first instance had granted relief but the appellate court reversed in favor of the first defendant. The BAG found the appeal of the first defendant admissible and successful, resulting in the final rejection of the plaintiff's demands; the specific legal doctrines or statutory norms forming the decisive basis for this dismissal are not detailed in the provided text, but the outcome confirms the validity of the defense against the specific labor law assertion.