Has an NBA game ever ended 82-78?
Yes. NBA has seen a final score of 82-78 25 times. It first happened on February 4, 1950, when Rochester Royals beat Chicago Stags, and most recently on January 5, 2014, when Indiana Pacers beat Cleveland Cavaliers.
That makes 82-78 the 861st most common final score out of 3,189 that have ever occurred in NBA. One point away, 83-78 has happened 27 times and 82-79 has happened 26 times. At one point the score disappeared for 38 years, between 1955 and 1993.