A Whole New Way to Get Screwed

This letter to an advice columnist points out a whole new way anti-union employers can screw their workers when they withdraw recognition. The writer's employer is subtracting pension benefits attributable to the union pension from the employer pension benefits, instituted after the employer illegally withdrew recognition. The columnist quotes a "pension rights" attorney (what the hell is that?) as saying its permissible but advises the writer to check the plan document. Does anyone know if the pension-rights attorney is wrong? I doubt it, but I'd love to hear otherwise.