Gibson Greetings, Inc., had a plant in Berea, Kentucky, where the workers belonged to the International Brotherhood of Firemen & Oilers. The old CBA expired, and the parties negotiated a new one, but were unable to reach an agreement on economic issues. The union struck. At the next bargaining session, the company claimed that the strike violated the old CBA, which had a no-strike clause and which stated that the terms of the old CBA would continue in force as long as the parties were bargaining a new CBA. The company refused to bargain until the union at least agreed that by bargaining, the company was not giving up its claim of an illegal strike. The two sides returned to bargaining, but meanwhile the company hired replacement workers. Eventually, the striking workers offered to return to work, but Gibson refused to rehire many of them. In court, the union claimed that the company had committed a ULP by (1) insisting the strike was illegal; and (2) refusing to bargain until the union acknowledged the company's position. Why is it very important to the union to establish the company's act as a ULP? Was it a ULP?