Has an NBA game ever ended 88-79?
It has. 88-79 has been a NBA final 41 times in 77,318 games. The first was Chicago Stags beat Cleveland Rebels on December 11, 1946; the latest was Memphis Grizzlies beat Utah Jazz on January 8, 2017.
That makes 88-79 the 598th most common final score out of 3,189 that have ever occurred in NBA. One point away, 89-79 has happened 29 times and 88-80 has happened 36 times.