In the case of National Labor Relations Board v. Burnup & Sims, Inc., 1964, the U.S. Supreme Court ruled in favor of the National Labor Relations Board (NLRB). The dispute arose when Burnup & Sims fired two employees for distributing union literature during work hours and on company property without permission. The NLRB argued that these actions were protected under section 7 of the National Labor Relations Act which allows employees to engage in concerted activities for mutual aid or protection. However, Burnup & Sims contended that they had a reasonable belief that such activity was disruptive to their business operations and therefore justified termination. The Supreme Court held that an employer cannot fire an employee based on a good-faith but mistaken belief about potential disruption from union-related activities unless there is evidence supporting this belief beyond mere suspicion or conjecture. In this case, no substantial evidence was presented by Burnup & Sims showing actual interference with work or breach of discipline due to distribution of union materials; thus it violated NLRA's provision against unfair labor practices by terminating those employees.

In the dissenting opinion for the National Labor Relations Board v. Burnup & Sims, Inc., Justice Harlan argued that the majority's decision was a departure from established principles of labor law and could potentially infringe upon an employer's right to maintain discipline in their workplace. He contended that there was no substantial evidence to support the claim that Burnup & Sims had violated Section 8(a)(1) of the National Labor Relations Act by firing two employees who engaged in protected concerted activities. According to him, these employees were not fired because they sought union representation but rather due to their disruptive behavior which included spreading false rumors about imminent layoffs. Justice Harlan emphasized that employers should have some latitude in maintaining order and discipline at work without being accused of unfair labor practices every time they take action against unruly or insubordinate workers engaging in union activities.