Sandra Falcone was employed as a dental hygiene assistance. During a staff metting, Dr. Trufolo discussed some work-related problems. Falcone and a coworker interrupted the meeting several times to disagree with Dr. Trufolo's comments. After the meeting, the office manager reprimanded Falcone and her coworker for disrupting that meeting by questioning Dr. Trufolo and by giggling and elbowing each other. On the following Monday, Falcone presented a lest of grievances to the office manager, which Flacone had discussed with cowrokers. Shortly thereafter, she was fired.
Vased on these facts, did the employer commit an unfair labor practice by discharging Falcone? Upon what facts should the NLRB determine the true motive for the discharge?